CVE-2026-74538 Bluetooth: ISO: lock sk in iso_connect_ind
A race condition in the Linux kernel Bluetooth ISO subsystem can lead to a null pointer dereference and system crash.
- 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-2026-74538?
CVE-2026-74538 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: lock sk in iso_connect_ind
Accessing iso_pi(sk)->conn requires lock_sock, which is not taken in the "ev3" part of iso_connect_ind. It may also be NULL if socket has transitioned away from the LISTEN/CONNECT states before locking.
Fix by adding lock/release. Recheck hcon is valid after lock acquire where needed.
Which versions are affected by CVE-2026-74538?
How do I fix CVE-2026-74538?
Apply the vendor's patch.
Is CVE-2026-74538 being exploited?
There is no known exploitation of CVE-2026-74538 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74538, DEBIAN-CVE-2026-74538, GHSA-hqwp-mg54-6754, UBUNTU-CVE-2026-74538.