Uncontrolled resource consumption in coturn
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA coturn (coturn) Fixed in 4.16.0
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-73214
References
Other 6
- https://github.com/coturn/coturn/security/advisories/GHSA-5x2p-4vqj-f6m4
- https://github.com/coturn/coturn/pull/2003
- https://github.com/coturn/coturn/pull/2012
- https://github.com/coturn/coturn/commit/37e13d1d60af8f1422c01b5e9f1c6bc355d03b85
- https://github.com/coturn/coturn/commit/beb4de9dcb6a475129595b943c9a34264420df09
- https://github.com/coturn/coturn/releases/tag/4.16.0
More coturn vulnerabilities
- TI-2026-32037 Coturn: Stack buffer overflow in decode_oauth_token_gcm() CVSS 3.1CRITICAL 9.8
- TI-2026-44985 Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`) CVSS 4.0HIGH 8.2
- TI-2026-29348 Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64) CVSS 3.1HIGH 7.5
- TI-2026-22006 Coturn: IPv4-mapped IPv6 (::ffff:0:0/96) bypasses denied-peer-ip ACL CVSS 3.1HIGH 7.2
- TI-2026-38529 Coturn: SQL Injection in HTTPS Admin Panel Delete Operations CVSS 3.1HIGH 7.2
- TI-2026-46994 Coturn: MOBILITY-TICKET session-resume authorization bypass allows cross-user TURN allocation takeover CVSS 3.1HIGH 7.1
Sources
- CVE-2026-73214 · CVE Program
- CVE-2026-73214 · NVD
- FIRST EPSS
- CVE-2026-73214 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences