Medium severity · published Aug 11, 2026
CVE-2026-73216
coturn: mobility disconnects bypass allocation quotas and exhaust relay capacity
6.5
CVSS
0.6%
EPSS
No
On KEV
Description
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.17.0, shutdown_client_connection() in src/server/ns_turn_server.c prematurely calls dec_quota() and releases bandwidth accounting during the first-stage close of a mobility-enabled allocation while preserving the allocation, relay socket, session, and mobility ticket, allowing an authenticated client to bypass --user-quota and --total-quota and exhaust relay ports. This issue is fixed in version 4.17.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
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
< 4.17.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73216
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73216
github.com
https://github.com/coturn/coturn/commit/3c5b2615fd405c4e7c5bf3fbeef895c94a90671b
github.com
https://github.com/coturn/coturn/releases/tag/4.17.0
github.com
https://github.com/coturn/coturn/security/advisories/GHSA-f6hc-79w3-p8pq
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