CVE-2026-27730

HIGH

7.5

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.

Details CVE

Score CVSS v3.17.5

SeveriteHIGH

Vecteur CVSSCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Vecteur d'attaqueNETWORK

ComplexiteLOW

Privileges requisNONE

Interaction utilisateurNONE

Publie2/25/2026

Derniere modification2/27/2026

Sourcenvd

Observations honeypot0

Produits affectes

esm:esm.sh

Faiblesses (CWE)

CWE-918

References

https://github.com/esm-dev/esm.sh/security/advisories/GHSA-p2v6-84h2-5x4r(security-advisories@github.com)

Correlations IOC

Aucune correlation enregistree

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