CVE-2026-53073 Bluetooth: hci_ldisc: Clear HCI_UART_PROTO_INIT on error
A null pointer dereference in the Linux kernel Bluetooth driver allows local attackers to cause a system crash via UART data processing errors.
- 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-2026-53073?
CVE-2026-53073 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 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_ldisc: Clear HCI_UART_PROTO_INIT on error
When hci_register_dev() fails in hci_uart_register_dev() HCI_UART_PROTO_INIT is not cleared before calling hu->proto->close(hu) and setting hu->hdev to NULL. This means incoming UART data will reach the protocol-specific recv handler in hci_uart_tty_receive() after resources are freed.
Clear HCI_UART_PROTO_INIT with a write lock before calling hu->proto->close() and setting hu->hdev to NULL. The write lock ensures all active readers have completed and no new reader can enter the protocol recv path before resources are freed.
This allows the protocol-specific recv functions to remove the "HCI_UART_REGISTERED" guard without risking a null pointer dereference if hci_register_dev() fails.
Weakness: CWE-476
Which versions are affected by CVE-2026-53073?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53073?
Apply the vendor's patch.
Is CVE-2026-53073 being exploited?
There is no known exploitation of CVE-2026-53073 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53073, DEBIAN-CVE-2026-53073, GHSA-wq7c-9cj9-76jg, ROOT-OS-DEBIAN-11-CVE-2026-53073, ROOT-OS-DEBIAN-12-CVE-2026-53073, ROOT-OS-UBUNTU-2204-CVE-2026-53073 and 2 more.