diff --git a/packages/api/src/files/documents/html.spec.ts b/packages/api/src/files/documents/html.spec.ts
index 681be2bf4d..54aa036e2f 100644
--- a/packages/api/src/files/documents/html.spec.ts
+++ b/packages/api/src/files/documents/html.spec.ts
@@ -123,10 +123,15 @@ describe('Office HTML producers', () => {
         );
         expect(cspMatch).not.toBeNull();
         const csp = cspMatch![1];
-        // The bomb defense: no outbound HTTP requests from the rendered
-        // iframe — a parser bug in docx-preview can't be turned into
-        // exfiltration of the embedded document content.
-        expect(csp).toMatch(/connect-src 'none'/);
+        /* `connect-src` is restricted to self + jsdelivr (where the
+         * renderer script came from). Allowing these is necessary for
+         * DevTools sourcemap fetches; broader exfiltration paths
+         * (arbitrary HTTPS, websockets, etc.) stay blocked. Manual
+         * e2e on PR #12934 — strict `'none'` filled DevTools console
+         * with `.min.js.map` violations every time the iframe was
+         * inspected. */
+        expect(csp).toMatch(/connect-src 'self' https:\/\/cdn\.jsdelivr\.net/);
+        expect(csp).not.toMatch(/connect-src[^;]*\*/); // no wildcard
         // No `<base>` tampering, no form submission either.
         expect(csp).toMatch(/base-uri 'none'/);
         expect(csp).toMatch(/form-action 'none'/);
@@ -438,7 +443,7 @@ describe('Office HTML producers', () => {
         expect(html).toContain('crossorigin="anonymous"');
       });
 
-      test('CSP locks the iframe down: connect-src none, no eval, no base/form tampering', async () => {
+      test('CSP locks the iframe down: connect-src restricted, no eval, no base/form tampering', async () => {
         const pptx = await buildPptx([{ title: 'X' }]);
         const html = await _internal.pptxToHtmlViaCdn(pptx);
         const cspMatch = html.match(
@@ -446,7 +451,14 @@ describe('Office HTML producers', () => {
         );
         expect(cspMatch).not.toBeNull();
         const csp = cspMatch![1];
-        expect(csp).toMatch(/connect-src 'none'/);
+        /* `connect-src` allows self + jsdelivr (the script's origin)
+         * so DevTools sourcemap fetches succeed and any same-origin
+         * fetches the renderer makes at runtime work. Wildcard
+         * exfiltration paths stay blocked. Manual e2e on PR #12934 —
+         * strict `'none'` filled DevTools console with `.min.js.map`
+         * violations every time the iframe was inspected. */
+        expect(csp).toMatch(/connect-src 'self' https:\/\/cdn\.jsdelivr\.net/);
+        expect(csp).not.toMatch(/connect-src[^;]*\*/); // no wildcard
         expect(csp).toMatch(/base-uri 'none'/);
         expect(csp).toMatch(/form-action 'none'/);
         expect(csp).toMatch(/script-src https:\/\/cdn\.jsdelivr\.net 'unsafe-inline'/);
diff --git a/packages/api/src/files/documents/html.ts b/packages/api/src/files/documents/html.ts
index baa723fd17..ae09282706 100644
--- a/packages/api/src/files/documents/html.ts
+++ b/packages/api/src/files/documents/html.ts
@@ -378,13 +378,25 @@ const OFFICE_HTML_OUTPUT_CAP = 512 * 1024;
  * styles into `<head>` at render time).
  */
 function buildDocxCdnDocument(base64: string, mammothFallbackHtml: string): string {
+  /* `connect-src` allows fetches to:
+   *   - `'self'`: the sandpack-static-server origin the iframe runs in
+   *     (covers any same-origin sourcemap fetches the bundler embedded)
+   *   - `https://cdn.jsdelivr.net`: where the renderer script came from
+   *     (DevTools fetches `.min.js.map` from the same host as the script
+   *     to map minified line numbers; with `'none'` the console fills
+   *     with CSP violations every time DevTools is open)
+   *
+   * Exfiltration risk is minimal: the iframe is cross-origin to the
+   * LibreChat host so an attacker can't read application data from it,
+   * and the only meaningful target ('self' or jsdelivr) isn't useful
+   * for exfiltrating slide content to a host the attacker controls. */
   const csp = [
     "default-src 'none'",
     "script-src https://cdn.jsdelivr.net 'unsafe-inline'",
     "style-src 'unsafe-inline'",
     "img-src 'self' data: blob:",
     'font-src data:',
-    "connect-src 'none'",
+    "connect-src 'self' https://cdn.jsdelivr.net",
     "base-uri 'none'",
     "form-action 'none'",
   ].join('; ');
@@ -1061,6 +1073,19 @@ function buildPptxCdnDocument(base64: string): string {
    *     visible symptom is a black iframe with the renderer half-
    *     started. Allowing blob:-only workers is the minimum surface to
    *     unblock rendering without permitting arbitrary worker URLs. */
+  /* `connect-src` allows fetches to:
+   *   - `'self'`: the sandpack-static-server origin the iframe runs in
+   *     (covers any same-origin fetches pptx-preview or its bundled
+   *     echarts make at render time, plus same-origin sourcemap loads)
+   *   - `https://cdn.jsdelivr.net`: where the renderer script came from
+   *     (DevTools fetches `.min.js.map` from there to map minified
+   *     line numbers; with `'none'` the console fills with CSP
+   *     violations every time DevTools is open)
+   *
+   * Exfiltration risk is minimal: the iframe is cross-origin to the
+   * LibreChat host so an attacker can't read application data, and
+   * the only meaningful targets ('self' or jsdelivr) aren't useful
+   * for exfiltrating slide content to a host the attacker controls. */
   const csp = [
     "default-src 'none'",
     "script-src https://cdn.jsdelivr.net 'unsafe-inline'",
@@ -1068,7 +1093,7 @@ function buildPptxCdnDocument(base64: string): string {
     'worker-src blob:',
     "img-src 'self' data: blob:",
     'font-src data:',
-    "connect-src 'none'",
+    "connect-src 'self' https://cdn.jsdelivr.net",
     "base-uri 'none'",
     "form-action 'none'",
   ].join('; ');