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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 12 Aug 2026 23:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 12 Aug 2026 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Coturn
Coturn coturn
Vendors & Products Coturn
Coturn coturn

Wed, 12 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important


Tue, 11 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
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.
Title coturn allocates a full per-peer SSL/session before verifying the DTLS cookie, enabling source-spoofing/botnet state-exhaustion DoS
Weaknesses CWE-400
CWE-770
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-12T22:13:33.373Z

Reserved: 2026-08-11T14:41:20.121Z

Link: CVE-2026-73214

cve-icon Vulnrichment

Updated: 2026-08-12T22:07:48.463Z

cve-icon NVD

Status : Received

Published: 2026-08-11T18:18:26.773

Modified: 2026-08-12T23:17:23.430

Link: CVE-2026-73214

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-11T17:34:51Z

Links: CVE-2026-73214 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-12T21:00:04Z

Weaknesses