esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, the legacy router first retrieves a response from legacyServer, parses the incoming request path, and ultimately writes the data to storage via buildStorage.Put. The router concatenates the path components without sanitizing them, producing a storage key. When this key is used, the underlying file system resolves the relative segments and writes the file to the specified path. Thus an attacker can craft a request that writes data to arbitrary locations on the server.
History

Thu, 28 May 2026 15:30:00 +0000

Type Values Removed Values Added
Description esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, the legacy router first retrieves a response from legacyServer, parses the incoming request path, and ultimately writes the data to storage via buildStorage.Put. The router concatenates the path components without sanitizing them, producing a storage key. When this key is used, the underlying file system resolves the relative segments and writes the file to the specified path. Thus an attacker can craft a request that writes data to arbitrary locations on the server.
Title esm.sh: Legacy Route Path Traversal Can Lead to RCE
Weaknesses CWE-22
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-28T14:44:20.782Z

Reserved: 2026-05-06T21:49:12.425Z

Link: CVE-2026-44593

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-28T16:16:24.587

Modified: 2026-05-28T16:16:24.587

Link: CVE-2026-44593

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.