Review reviewCritical

CVE-2026-33943

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. In versions 15.10.0 through 20.8.7, a code injection vulnerability in `ECMAScriptModuleCompiler` allows an attacker to achieve Remote Code Execution (RCE) by injecting arbitrary JavaScript expressions inside `export { }` declarations in ES module scripts processed by happy-dom. The compiler directly interpolates unsanitized content into generated code as an executable expression, and the quote filter does not strip backticks, allowing template literal-based payloads to bypass sanitization. Versio...

CVSS: 9.8
EPSS: 0.79%
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 probability0.79%

Technical severityCVSS 9.8

Vulnerability overview

Affected product and versions

Product: capricorn86 happy-dom, Red Hat Ansible Automation Platform 2, Red Hat OpenShift Container Platform 4
Affected versions: >= >= 15.10.0, < 20.8.8, >= 15.10.0 < 20.8.8
Fixed versions: 20.8.8

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:H/A:H
CWE: CWE-917, CWE-94