Happy DOM's fetch credentials include uses page-origin cookies instead of target-origin cookies
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
exploitation probability
0.5%top 61% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
capricorn86 · happy-domReferences
https://access.redhat.com/security/cve/CVE-2026-34226https://bugzilla.redhat.com/show_bug.cgi?id=2452519https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.tshttps://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751https://github.com/capricorn86/happy-dom/pull/2117https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4ghttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34226.json