CVE-2026-27586

CRITICAL

9.1

Description

Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, two swallowed errors in `ClientAuthentication.provision()` cause mTLS client certificate authentication to silently fail open when a CA certificate file is missing, unreadable, or malformed. The server starts without error but accepts any client certificate signed by any system-trusted CA, completely bypassing the intended private CA trust boundary. Any deployment using `trusted_ca_cert_file` or `trusted_ca_certs_pem_files` for mTLS will silently degrade to accepting any system-trusted client certificate if the CA file becomes unavailable. This can happen due to a typo in the path, file rotation, corruption, or permission changes. The server gives no indication that mTLS is misconfigured. Version 2.11.1 fixes the vulnerability.

Details CVE

Score CVSS v3.19.1

SeveriteCRITICAL

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

Vecteur d'attaqueNETWORK

ComplexiteLOW

Privileges requisNONE

Interaction utilisateurNONE

Publie2/24/2026

Derniere modification2/25/2026

Sourcenvd

Observations honeypot0

Produits affectes

caddyserver:caddy

Faiblesses (CWE)

CWE-755

References

https://gist.github.com/moscowchill/9566c79c76c0b64c57f8bd0716f97c48(security-advisories@github.com)

https://github.com/caddyserver/caddy/releases/tag/v2.11.1(security-advisories@github.com)

https://github.com/caddyserver/caddy/security/advisories/GHSA-hffm-g8v7-wrv7(security-advisories@github.com)

Correlations IOC

Aucune correlation enregistree

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