Bug 2514259 (CVE-2026-73214)

Summary: CVE-2026-73214 coturn: coturn: Denial of Service via unverified DTLS session state
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in coturn. This vulnerability allows an unauthenticated remote attacker to cause a Denial of Service (DoS) by sending specially crafted fragmented ClientHello messages. The coturn server retains OpenSSL Datagram Transport Layer Security (DTLS) session state for these messages before validating the DTLS cookie, leading to excessive memory consumption and resource exhaustion.
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Description OSIDB Bzimport 2026-08-11 18:02:23 UTC 
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.