cvedb.io
CVE-2026-27730
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-02-25T16:23:27.123 · Last modified 2026-06-17T10:27:34.187

Summary

esm.sh is a no-build content delivery network (CDN) for web development. Versions up to and including 137 have an SSRF vulnerability (CWE-918) in esm.sh’s `/http(s)` fetch route. The service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypassed using DNS alias domains. This allows an external requester to make the esm.sh server fetch internal localhost services. As of time of publication, no known patched versions exist.

Affected products

esm — esm.sh

Does this affect you?

Add your gear to cvedb and we'll alert you only when esm ships something exploited.

Check my exposure →

References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.