Description

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.

INFO

Published Date :

2026-02-25T15:37:01.753Z

Last Modified :

2026-02-25T20:32:05.079Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2026-27730 vulnerability.

Vendors Products
Esm
  • Esm.sh
Esm-dev
  • Esmsh
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-27730.

URL Resource
https://github.com/esm-dev/esm.sh/security/advisories/GHSA-p2v6-84h2-5x4r cve-icon cve-icon
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Detailed values of each vector for above chart.
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Integrity Impact
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