A read buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. This occurs after certificate chain signature verification and requires either a CA to have signed the malicious certificate or for the application to continue certificate verification despite failure to construct a path to a trusted issuer. The read buffer overrun might result in a crash, which could lead to a denial of service attack. In theory, it could also result in the disclosure of private memory contents, such as private keys or sensitive plaintext, although no working exploit leading to memory contents disclosure is known at the time of release of this advisory. In a TLS client, this can be triggered by connecting to a malicious server. In a TLS server, this can be triggered if the server requests client authentication and a malicious client connects.