VulnerabilityModified
CVE-2026-34226
This can leak cookies from origin A to destination B.
HIGH 7.5EPSS 0.46%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.46% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-201, CWE-359
- Affected
- capricorn86/happy dom
- Source
- security-advisories@github.com
References
- https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.tsPatch
- https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751Patch
- https://github.com/capricorn86/happy-dom/pull/2117Issue Tracking, Patch
- https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9Product, Release Notes
- https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4gExploit, 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.