OpenSSL 4.1.0 finally ships DTLS 1.3, four known bugs included

On October 23, 2026, OpenSSL released version 4.1.0, which adds DTLS 1.3 (RFC 9147) support alongside four known bugs in that same code, two of which make a connection’s return codes lie to the application. If you adopt DTLS 1.3 server-side, do not take SSL_ERROR_WANT_READ or SSL_ERROR_SYSCALL at face value.