CVE-2026-68554 Security feature bypass in coturn
On-path attackers can modify authenticated TURN requests by appending attributes after MESSAGE-INTEGRITY, bypassing integrity checks and altering server behavior.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68554?
CVE-2026-68554 is a low-severity vulnerability in coturn, published on 19 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, an on-path attacker can append attributes after MESSAGE-INTEGRITY to an authenticated STUN request on plain UDP or TCP, adjust the STUN header length, and recompute the unkeyed FINGERPRINT while the original HMAC remains valid because it covers only the message prefix. Server-side parsing in src/server/ns_turn_server.c continues past MESSAGE-INTEGRITY through handle_turn_allocate(), handle_turn_create_permission(), handle_turn_refresh(), and handle_turn_command(), allowing trailing LIFETIME, XOR-PEER-ADDRESS, or ORIGIN attributes to override allocation lifetime, inject a permission, or bypass the origin check. TLS and DTLS deployments prevent this in-transit modification. This issue is fixed in version 4.15.0.
Which versions are affected by CVE-2026-68554?
How do I fix CVE-2026-68554?
Upgrade to a fixed version.
Is CVE-2026-68554 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-68554 exists.
Sources
Also known as DEBIAN-CVE-2026-68554, GHSA-5538-7cxj-5jcc, UBUNTU-CVE-2026-68554.