CVE-2026-34226

HIGH EPSS 32.5%
Published Mar 27, 20263mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Mar 27, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability None

Threat Intelligence

EPSS Exploit Probability
32.5% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 2

CWE-201
CWE-359

Affected Products 1

VendorProductVersionRange
capricorn86happy_dom* <20.8.9

References 5

  • github.com https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts
    Patch
  • github.com https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751
    Patch
  • github.com https://github.com/capricorn86/happy-dom/pull/2117
    Issue TrackingPatch
  • github.com https://github.com/capricorn86/happy-dom/releases/tag/v20.8.9
    ProductRelease Notes
  • github.com https://github.com/capricorn86/happy-dom/security/advisories/GHSA-w4gp-fjgq-3q4g
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts
    Patch
  • github.com https://github.com/capricorn86/happy-dom/commit/68324c21d7b98f53f7bb5a7b3e185bda7106e751
    Patch
  • github.com https://github.com/capricorn86/happy-dom/pull/2117
    Issue TrackingPatch