CVE-2026-34226

HIGH

Happy DOM's fetch credentials include uses page-origin cookies instead of target-origin cookies

Title source: cna

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.

References (5)

[X_Refsource_Confirm] https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4g

[X_Refsource_Misc] https://github.com/capricorn86/happy-dom/pull/2117

[X_Refsource_Misc] https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751

[X_Refsource_Misc] https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts

View Writeup ZIP pw:eip

[X_Refsource_Misc] https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9

Scores

CVSS v3 7.5

EPSS 0.0004

EPSS Percentile 11.3%

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