esm-dev esm.sh up to 136 HTTP Header X-Zone-Id path traversal

Summaryinfo

A vulnerability was found in esm-dev esm.sh up to 136. It has been classified as critical. Affected is an unknown function of the component HTTP Header Handler. This manipulation of the argument X-Zone-Id causes path traversal. This vulnerability appears as CVE-2025-59342. The attack may be initiated remotely. In addition, an exploit is available.

Detailsinfo

A vulnerability was found in esm-dev esm.sh up to 136. It has been declared as critical. Affected by this vulnerability is an unknown code block of the component HTTP Header Handler. The manipulation of the argument X-Zone-Id with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-24. The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize "../" sequences that can resolve to a location that is outside of that directory. As an impact it is known to affect integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2025-59342 since 09/12/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known. The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Exploit-DB (52461). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• esm-dev

Name

• esm.sh

Version

• 136

Website

• Product: https://github.com/esm-dev/esm.sh/

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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