CVEvulnerability
CVE-2026-33943
9.8 CRITICAL
Official page ↗
- Status
- Modified
- Published
- 2026-03-27
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CVSS 3.1 ([email protected])
- 9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CVSS 3.1 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)
- 8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-917, CWE-94
Description
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. Version 20.8.8 fixes the issue.
Affected configurations
• capricorn86 happy dom (>= 15.10.0 < 20.8.8)
Related
References
- https://github.com/capricorn86/happy-dom/commit/5437fdf8f13adb9590f9f52616d9f69c3ee8db3c Patch
- https://github.com/capricorn86/happy-dom/releases/tag/v20.8.8 Product, Release Notes
- https://github.com/capricorn86/happy-dom/security/advisories/GHSA-6q6h-j7hj-3r64 Exploit, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-33943 access.redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=2452522 bugzilla.redhat.com
- https://github.com/capricorn86/happy-dom/security/advisories/GHSA-6q6h-j7hj-3r64 Exploit, Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33943.json security.access.redhat.com