Review reviewHigh

CVE-2026-34226

capricorn86 happy-dom, Red Hat Ansible Automation Platform 2, Red Hat OpenShift Container Platform 4

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: 7.5
EPSS: 0.46%
CISA KEV: Not listed
Published: 2026.03.28

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.46%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: capricorn86 happy-dom, Red Hat Ansible Automation Platform 2, Red Hat OpenShift Container Platform 4
Affected versions: >= < 20.8.9, < 20.8.9
Fixed versions: 20.8.9

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that capricorn86 happy-dom, Red Hat Ansible Automation Platform 2, Red Hat OpenShift Container Platform 4 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE: CWE-201, CWE-359