PT-2025-38248 · Esm Dev · Esm.Sh

Published 2025-09-17 · Updated 2025-09-17 · CVE-2025-59342

NVD

CVSS v4.0

5.5

5.5

Medium

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

Fix

Weakness Enumeration

CWE-24

Related Identifiers

CVE-2025-59342

Affected Products

Esm.Sh

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2025-59342 · Security Note
• https://twitter.com/j3ssiejjj/status/1968326917402324994 · Twitter Post
• https://github.com/esm-dev/esm.sh/security/advisories/GHSA-g2h5-cvvr-7gmw · Note
• https://github.com/esm-dev/esm.sh/blob/main/server/router.go#L116 · Note
• https://github.com/esm-dev/esm.sh/blob/main/server/router.go#L411 · Note