CVE-2026-90092 Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN
A race condition in the Linux kernel Bluetooth L2CAP subsystem allows a use-after-free, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90092?
CVE-2026-90092 is a high-severity use after free vulnerability in Linux, published on 17 Sep 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: L2CAP: reject accept queue add unless BT_LISTEN
New sk should not be added to parent socket accept queue after last l2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and state set to BT_CLOSED, as that can result to UAF on dereferencing the dangling parent reference.
l2cap_sock_new_connection_cb() may race with parent l2cap_chan teardown, due to chan->state accessed without consistent locking:
[Task 1] [Task 2] l2cap_sock_release(parent) l2cap_connect l2cap_sock_shutdown pchan = l2cap_global_chan_by_psm l2cap_chan_lock(pchan) l2cap_chan_close l2cap_sock_teardown_cb pchan->state = BT_CLOSED l2cap_chan_unlock(pchan) ------> l2cap_chan_lock(pchan) l2cap_new_connection l2cap_sock_new_connection_cb l2cap_chan_lock(pchan) <-------- l2cap_chan_unlock(pchan) l2cap_sock_kill(parent) /* bt_sk(sk)->parent dangling */
Fix by adding check for sk_state == BT_LISTEN after acquiring sk lock in l2cap_sock_new_connection_cb(). Add lock_sock() around sk_state writes where missing, to avoid data races.
Although the data races on pchan->state should be fixed too, this defensive sk_state check probably makes sense in any case.
Which versions are affected by CVE-2026-90092?
How do I fix CVE-2026-90092?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-90092 being exploited?
There is no known exploitation of CVE-2026-90092 in the wild and no public exploit code.
Sources
Also known as AZL-102993, BELL-CVE-2026-90092, DEBIAN-CVE-2026-90092, GHSA-6f8j-3px9-h4jj, UBUNTU-CVE-2026-90092.