CVE-2026-73214
HighCVSS 8.2Exploitation Probability (EPSS)
Low risk35th percentile - higher than 35% of all known CVEs
Summary
Coturn before version 4.16.0 has a vulnerability in dtls_server_input_handler() and create_new_connected_udp_socket() that retain OpenSSL dtls1_reassemble_fragment() state for a 35-byte fragmented ClientHello declaring a 650,000-byte handshake before cookie validation. An unauthenticated remote sender can exhaust memory without TURN credentials, a completed handshake, a valid cookie, or source spoofing.
Risk Assessment
The attack can lead to memory exhaustion on the server, potentially causing service outage and disruptions for all users.
Recommendation
Update Coturn to version 4.16.0 or later and restrict access to DTLS ports to trusted sources only.
Original NVD description (English source)
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.16.0, dtls_server_input_handler() and create_new_connected_udp_socket() in src/apps/relay/dtls_listener.c retain OpenSSL dtls1_reassemble_fragment() state for a 35-byte fragmented ClientHello declaring a 650,000-byte handshake before cookie validation, allowing an unauthenticated remote sender using fresh UDP tuples to exhaust memory without TURN credentials, a completed handshake, a valid cookie, or source spoofing. This issue is fixed in version 4.16.0.