CVE-2026-23644 HIGH

CVE-2026-23644: esm.sh has path traversal in `extractPackageTarball` that enables file writes from malicious packages

Vendor Esm-Dev
Product esm.sh
Weakness CWE-22 · Path traversal
Published January 18, 2026
Last update January 20, 2026
View on NVD All CVEs

CVSS base score

7.7/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

What the vulnerability does

01Description

esm.sh is a no-build content delivery network (CDN) for web development. Prior to Go pseeudoversion 0.0.0-20260116051925-c62ab83c589e, the software has a path traversal vulnerability due to an incomplete fix. `path.Clean` normalizes a path but does not prevent absolute paths in a malicious tar file. Commit https://github.com/esm-dev/esm.sh/commit/9d77b88c320733ff6689d938d85d246a3af9af16, corresponding to pseudoversion 0.0.0-20260116051925-c62ab83c589e, fixes this issue.

Key dates

02Disclosure timeline

January 18, 2026 CVE published
January 20, 2026 Record updated