CVE-2026-68393 Bluetooth: hci_sync: extend conn_hash lookup critical sections
A use-after-free vulnerability in the Linux kernel Bluetooth subsystem allows attackers to potentially execute code or cause a denial of service.
- 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-2026-68393?
CVE-2026-68393 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: hci_sync: extend conn_hash lookup critical sections
Using RCU-protected pointers outside the critical sections without refcount is incorrect and may result to UAF.
Extend critical section to cover both hci_conn_hash lookup and use of the returned conn.
Add surrounding rcu_read_lock() also when return value is not used, in preparation for RCU lockdep requirement to hci_lookup_le_connect().
This avoids concurrent deletion of the conn before we are done dereferencing it.
Also, make sure to hold hdev->lock when accessing hdev->accept_list.
Weakness: CWE-416
Which versions are affected by CVE-2026-68393?
How do I fix CVE-2026-68393?
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-2026-68393 being exploited?
There is no known exploitation of CVE-2026-68393 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68393, DEBIAN-CVE-2026-68393, GHSA-mrp3-x3ff-8xj3, UBUNTU-CVE-2026-68393.