CVE-2026-34226
HIGHHappy DOM's fetch credentials include uses page-origin cookies instead of target-origin cookies
Title source: cnaDescription
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.
References (8)
Core 8
Core References
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-34226
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2452519
X_Refsource_Confirm x_refsource_confirm
https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4g
X_Refsource_Misc x_refsource_misc
https://github.com/capricorn86/happy-dom/pull/2117
X_Refsource_Misc x_refsource_misc
https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751
X_Refsource_Misc x_refsource_misc
https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts
X_Refsource_Misc x_refsource_misc
https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9
Scores
CVSS v3
7.5
EPSS
0.0046
EPSS Percentile
37.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-201
CWE-359
Status
published
Products (3)
capricorn86/happy-dom
< 20.8.9
capricorn86/happy_dom
< 20.8.9
npm/happy-dom
0 - 20.8.9npm
Published
Mar 27, 2026
Tracked Since
Mar 29, 2026