CVE-2025-59342
esm.sh writes arbitrary files via path traversal in `X-Zone-Id` header
- State
- Published
- Severity
- 5.5 Medium
- Published
- Sep 17, 2025
- Updated
- Jan 14, 2026
- Reserved
- Sep 12, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.5 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P | GitHub_M |
Weaknesses
- CWE-24 Path Traversal: '../filedir'
Affected Products
| Product | Versions |
|---|---|
esm.shesm-dev |
|
References
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