VULNERABILITY INTELLIGENCE

CVE-2025-65026

CVSS score6.1 MEDIUM
EPSS probability0.51%
CISA KEVNot currently listed
Published2025-11-19
Last modified2026-10-18
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Description

esm.sh is a nobuild content delivery network(CDN) for modern web development. Prior to version 136, The esm.sh CDN service contains a Template Literal Injection vulnerability (CWE-94) in its CSS-to-JavaScript module conversion feature. When a CSS file is requested with the ?module query parameter, esm.sh converts it to a JavaScript module by embedding the CSS content directly into a template literal without proper sanitization. An attacker can inject malicious JavaScript code using ${...} expressions within CSS files, which will execute when the module is imported by victim applications. This enables Cross-Site Scripting (XSS) in browsers and Remote Code Execution (RCE) in Electron applications. This issue has been patched in version 136.

Weakness classification

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-94: Improper Control of Generation of Code ('Code Injection')

Primary references