CVE-2026-73216 coturn: mobility disconnects bypass allocation quotas and exhaust relay capacity
An authenticated client can bypass allocation quotas and exhaust relay ports in Coturn when mobility is enabled, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73216?
CVE-2026-73216 is a medium-severity denial of service vulnerability in coturn, published on 11 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-73216?
How do I fix CVE-2026-73216?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-73216 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73216 exists.
Sources
Also known as DEBIAN-CVE-2026-73216, GHSA-f6hc-79w3-p8pq, MINI-pq85-rhgj-wgpg, UBUNTU-CVE-2026-73216.