VULNERABILITY INTELLIGENCE

CVE-2026-33943

CVSS score8.8 HIGH
EPSS probability0.65%
CISA KEVNot currently listed
Published2026-03-27
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

Weakness classification

  • security-advisories@github.com: CWE-94
  • 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-917

Primary references