CVE-2026-68085 Bluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled
A race condition in the Linux kernel Bluetooth driver fails to clear a state flag, causing a denial of service by blocking future writes after device reopening.
- 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-2026-68085?
CVE-2026-68085 is a high-severity 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: hci_uart: clear HCI_UART_SENDING when write_work is canceled
HCI_UART_SENDING bit in tx_state means write_work is pending and blocks queueing it again. Currently this bit is not cleared when canceling the work in hci_uart_close(), which blocks future writes when device is reopened later if write_work was pending.
Fix by clearing HCI_UART_SENDING when canceling the work.
Also make clearing of tx_skb safe by using disable_work_sync + enable_work instead of just cancel_work_sync. hci_uart_flush() purges the proto tx queue so we can cancel the pending write_work there, instead of doing it just in hci_uart_close(). Re-enable and possibly requeue the work after queue flush.
Weakness: CWE-667
Which versions are affected by CVE-2026-68085?
How do I fix CVE-2026-68085?
Apply the vendor's patch.
Is CVE-2026-68085 being exploited?
There is no known exploitation of CVE-2026-68085 in the wild and no public exploit code.
Sources
Also known as AZL-95147, BELL-CVE-2026-68085, DEBIAN-CVE-2026-68085, GHSA-mhcf-ghw6-c6wv, UBUNTU-CVE-2026-68085.