CVE-2026-23644CWE-22

esm.sh has path traversal in `extractPackageTarball` that enables file writes from malicious packages

High · published January 18, 2026

CVSS v4.0
7.7
EPSS
1%
Percentile
45.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.7 · HIGH
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
EPSS
0.00560 · 45.9th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-01-18T22:49Z
EPSS history
Timeline
  • 18 JAN 22:49Z
    esm.sh has path traversal in `extractPackageTarball` that enables file writes from malicious packages
    cvelistv5