CVE-2026-53072 Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER
A race condition in the Linux kernel Bluetooth subsystem allows a use-after-free, potentially leading to code execution or privilege escalation.
- 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-2026-53072?
CVE-2026-53072 is a high-severity use after free 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: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER
When protocol sets HCI_PROTO_DEFER, hci_conn_request_evt() calls hci_connect_cfm(conn) without hdev->lock. Generally hci_connect_cfm() assumes it is held, and if conn is deleted concurrently -> UAF.
Only SCO and ISO set HCI_PROTO_DEFER and only for defer setup listen, and HCI_EV_CONN_REQUEST is not generated for ISO. In the non-deferred listening socket code paths, hci_connect_cfm(conn) is called with hdev->lock held.
Fix by holding the lock.
Which versions are affected by CVE-2026-53072?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53072?
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-2026-53072 being exploited?
There is no known exploitation of CVE-2026-53072 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53072, DEBIAN-CVE-2026-53072, GHSA-h99j-gm55-rrcw, ROOT-OS-DEBIAN-11-CVE-2026-53072, ROOT-OS-DEBIAN-12-CVE-2026-53072, ROOT-OS-UBUNTU-2204-CVE-2026-53072 and 2 more.