Vulnerability · Published Nov 19, 2025 · Assigned by GitHub_M
CVE-2025-65025esm.sh CDN service has arbitrary file write via tarslip
High 8.2
In plain English
A high-severity path traversal in esm.sh from esm-dev. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
esm.sh is a nobuild content delivery network(CDN) for modern web development. Prior to version 136, the esm.sh CDN service is vulnerable to path traversal during NPM package tarball extraction. An attacker can craft a malicious NPM package containing specially crafted file paths (e.g., package/../../tmp/evil.js). When esm.sh downloads and extracts this package, files may be written to arbitrary locations on the server, escaping the intended extraction directory. This issue has been patched in version 136.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/esm-dev/esm.sh | 0.0.0-20251117232647-9d77b88c3207 | GHSA-h3mw-4f23-gwpw |
| Go | github.com/esm-dev/esm.sh | 0.0.0-20251117232647-9d77b88c3207 | GO-2025-4138 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N