Advisories for Golang/Github.com/Caddyserver/Caddy/V2/Modules/Caddytls package

2026

Caddy: mTLS client authentication silently fails open when CA certificate file is missing or malformed

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.