High severity · published Aug 11, 2026
CVE-2026-73214
coturn allocates a full per-peer SSL/session before verifying the DTLS cookie, enabling source-spoofing/botnet state-exhaustion DoS
8.2
CVSS
0.6%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CO
coturn · coturn
< 4.16.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73214
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73214
github.com
https://github.com/coturn/coturn/commit/37e13d1d60af8f1422c01b5e9f1c6bc355d03b85
github.com
https://github.com/coturn/coturn/commit/beb4de9dcb6a475129595b943c9a34264420df09
github.com
https://github.com/coturn/coturn/pull/2003
github.com
https://github.com/coturn/coturn/pull/2012
github.com
https://github.com/coturn/coturn/releases/tag/4.16.0
github.com
https://github.com/coturn/coturn/security/advisories/GHSA-5x2p-4vqj-f6m4
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