CVE-2026-73214
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.42% probability · 36th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-770
- Source
- security-advisories@github.com
References
- https://github.com/coturn/coturn/commit/37e13d1d60af8f1422c01b5e9f1c6bc355d03b85
- https://github.com/coturn/coturn/commit/beb4de9dcb6a475129595b943c9a34264420df09
- https://github.com/coturn/coturn/pull/2003
- https://github.com/coturn/coturn/pull/2012
- https://github.com/coturn/coturn/releases/tag/4.16.0
- https://github.com/coturn/coturn/security/advisories/GHSA-5x2p-4vqj-f6m4
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.