CVE-2025-65026

esm.sh CDN service has JS Template Literal Injection in CSS-to-JavaScript

Published Nov 19, 2025 CVSS 3.1 · 6.1 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Github GHSA Github GHSA GHSA-hcpf-qv9m-vfgp esm.sh CDN service has JS Template Literal Injection in CSS-to-JavaScript
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Esm
Esm esm.sh
Weaknesses CWE-79
CPEs cpe:2.3:a:esm:esm.sh:*:*:*:*:*:*:*:*
Vendors & Products Esm
Esm esm.sh
Type Values Removed Values Added
First Time appeared Esm-dev
Esm-dev esmsh
Vendors & Products Esm-dev
Esm-dev esmsh
Type Values Removed Values Added
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.
Title esm.sh CDN service has JS Template Literal Injection in CSS-to-JavaScript
Weaknesses CWE-94
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 20, 2025, 2:19 PM
Reserved
Nov 13, 2025, 3:36 PM
Status
Analyzed
Published
Nov 19, 2025, 6:15 PM
Modified
Oct 18, 2026, 8:10 PM