CVE-2026-27586 Caddy's mTLS client authentication silently fails open when CA certificate file is missing or malformed

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...

CVE-2026-27586 Caddy's mTLS client authentication silently fails open when CA certificate file is missing or malformed

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...

CVE-2026-27586

Summary (CVE-2026-27586): Caddy prior to 2.11.1 has two swallowed errors in ClientAuthentication.provision() that cause mTLS client authentication to silently fail open when the CA certificate file is missing, unreadable, or malformed. The server starts and accepts client certs signed by any syst...