CVSS v3.1
N/A
CVSS v4.0
5.5
EPSS
2.83%
Published
Sep 17, 2025
Modified
Apr 14, 2026
Public PoC / Exploit (3)
All weaponized →Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.
Description
esm.sh is a nobuild content delivery network(CDN) for modern web development. In 136 and earlier, a path-traversal flaw in the handling of the X-Zone-Id HTTP header allows an attacker to cause the application to write files outside the intended storage location. The header value is used to build a filesystem path but is not properly canonicalized or restricted to the application’s storage base directory. As a result, supplying ../ sequences in X-Zone-Id causes files to be written to arbitrary directories. Version 136.1 contains a patch.
Weaknesses (CWE)
References (4)