GoAhead's verifyClientCertificate() (src/openssl.c) checks the client-certificate chain depth only when the verifier has not already reported an error. When built against LibreSSL's legacy verifier (3.2.x, 3.3.2-3.3.6) with VERIFY_PEER=1 and VERIFY_ISSUER=0, an attacker can present a self-signed chain longer than the limit of 10 and pass mutual TLS without any trusted key. OpenSSL builds are not affected. Affects versions up to and including 6.1.0; fixed in 6.1.1.