CVE-2025-59342

CVE-2025-59342 is a medium-severity vulnerability with a CVSS 4.0 base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-24.

Key facts

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.

Frequently asked questions

What is CVE-2025-59342?
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.
How severe is CVE-2025-59342?
CVE-2025-59342 has a CVSS 4.0 base score of 5.5, rated medium severity.
Is CVE-2025-59342 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-59342?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-59342 have an EU (EUVD) identifier?
Yes. CVE-2025-59342 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-29764.
When was CVE-2025-59342 published?
CVE-2025-59342 was published on 2025-09-17 and last updated on 2026-06-17.

References

Other CWE-24 vulnerabilities

Browse all CWE-24 vulnerabilities →