CVE-2026-73215 The coturn server can end in a state where it does not accept more requests with "even-port" enabled.
An authenticated attacker can exhaust the relay port pool in coturn when even-port mode is enabled, causing subsequent allocation failures and 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-2026-73215?
CVE-2026-73215 is a high-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, turnports_allocate_even() in src/apps/relay/turn_ports.c marks the unused odd sibling port as TPS_TAKEN_ODD for an EVEN-PORT Allocate request with reservation bit R=0 even though no RTCP socket will release it, allowing an authenticated client to permanently exhaust the relay port pool and cause subsequent allocations to fail with STUN error 508. This issue is fixed in version 4.17.0.
Which versions are affected by CVE-2026-73215?
How do I fix CVE-2026-73215?
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-2026-73215 being exploited?
There is no known exploitation of CVE-2026-73215 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-73215, GHSA-847g-qmc6-6m4r, MINI-gqrm-9h5x-q328, UBUNTU-CVE-2026-73215.