Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Versions prior to 20.8.9 may attach cookies from the current page origin (`window.location`) instead of the request target URL when `fetch(..., { credentials: "include" })` is used. This can leak cookies from origin A to destination B. Version 20.8.9 fixes the issue.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts Patch
- https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751 Patch
- https://github.com/capricorn86/happy-dom/pull/2117 Issue Tracking, Patch
- https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4g Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · capricorn86NVD modified 2026-10-26 21:10
Affected (CPE criteria) 1
cpe:2.3:a:capricorn86:happy_dom:*:*:*:*:*:node.js:*:*
References 8
- https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts Patch
- https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751 Patch
- https://github.com/capricorn86/happy-dom/pull/2117 Issue Tracking, Patch
- https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9 Product, Release Notes
- https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4g Exploit, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-34226
- https://bugzilla.redhat.com/show_bug.cgi?id=2452519
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34226.json