Threats tagged 'rustsec-2026-0347'

A vulnerability in rustls versions >=0.23.44 and <0.23.46 causes buffered application data to be sent to the outer server after Encrypted Client Hello (ECH) rejection. This occurs when the client writes application data before the handshake completes and the server rejects the ECH config. The client incorrectly sends plaintext application data to the client-facing server authenticated by the ECH config's public_name, violating RFC 9849 requirements. The issue is fixed in rustls 0.23.46.