CVE-2026-68394 Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update
A use-after-free vulnerability in the Linux kernel Bluetooth subsystem allows attackers to cause a denial of service or potentially execute code via crafted Bluetooth management operations.
- 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-2026-68394?
CVE-2026-68394 is a high-severity use after free vulnerability in Linux, published on 10 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: MGMT: revalidate LOAD_CONN_PARAM queued update
MGMT_OP_LOAD_CONN_PARAM queues conn_update_sync() when a single parameter update changes an existing LE central connection. The queued work currently stores a borrowed hci_conn_params entry from hdev->le_conn_params. A later LOAD_CONN_PARAM request can clear disabled parameters and free that entry before hci_cmd_sync_work() runs the queued callback.
Do not keep the borrowed hci_conn_params pointer in queued work. Queue the hci_conn instead and hold a reference until the queued callback completes. When the work runs, revalidate that the connection is still present, look up the current hci_conn_params entry, and cancel the update if userspace removed that entry while the work was pending.
Copy the interval values from the current params entry under hdev->lock, then drop the lock and keep using hci_le_conn_update_sync() to issue the update.
Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in conn_update_sync+0x2a/0xf0 [bluetooth] Read of size 1 at addr ffff88810c697126 by task kworker/u17:0/377 Workqueue: hci0 hci_cmd_sync_work [bluetooth]
Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 kasan_report+0xe0/0x110 conn_update_sync+0x2a/0xf0 [bluetooth] hci_cmd_sync_work+0x187/0x210 [bluetooth] process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30
Allocated by task 466: hci_conn_params_add+0xa6/0x240 [bluetooth] load_conn_param+0x4e1/0x850 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth]
Freed by task 474: kfree+0x313/0x590 hci_conn_params_clear_disabled+0x9b/0xc0 [bluetooth] load_conn_param+0x4bf/0x850 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth]
Weakness: CWE-416
Which versions are affected by CVE-2026-68394?
How do I fix CVE-2026-68394?
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-2026-68394 being exploited?
There is no known exploitation of CVE-2026-68394 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68394, DEBIAN-CVE-2026-68394, GHSA-7rj8-gwgq-wrff, UBUNTU-CVE-2026-68394.