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CVE-2026-34226 Details

Description

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.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: redhat-SADPCVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://access.redhat.com/security/cve/CVE-2026-34226	redhat-SADP
https://bugzilla.redhat.com/show_bug.cgi?id=2452519	redhat-SADP
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34226.json	redhat-SADP
https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts	[email protected]	Patch
https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751	[email protected]	Patch
https://github.com/capricorn86/happy-dom/pull/2117	[email protected]	Issue TrackingPatch
https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9	[email protected]	ProductRelease Notes
https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4g	[email protected]	ExploitVendor Advisory

see all 8 references

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-201	Insertion of Sensitive Information Into Sent Data	redhat-SADP
CWE-201	Insertion of Sensitive Information Into Sent Data	[email protected]
CWE-359	Exposure of Private Personal Information to an Unauthorized Actor	[email protected]

Affected Products

Product	Versions
capricorn86 happy dom	< 20.8.9
CPE cpe:2.3:a:capricorn86:happy_dom::::::node.js::* Remediation No remediation found in references.

Change History

7 change records found show changes

Date	Action	Recorded By
Aug 19, 2026	CPE Deprecation Remap	[email protected]
Jul 15, 2026	CVE Modified	redhat-SADP
Jun 30, 2026	CVE Modified	redhat-SADP
Jun 17, 2026	CVE Modified	CISA-ADP
Jun 17, 2026	CVE Modified	[email protected]
Apr 1, 2026	Initial Analysis	[email protected]
Mar 27, 2026	New CVE Received	[email protected]