SB20260720298 - Use-after-free in Linux kernel bluetooth
Published: July 20, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-63944)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in hci_le_create_cis_sync in the Bluetooth HCI synchronization logic when processing concurrent Bluetooth connection state changes during LE Create CIS handling. A local user can trigger a concurrent disconnect to cause a denial of service.
The stale pointer is dereferenced after both rcu_read_lock() and hci_dev_lock(hdev) are released, and the queued cancellation path does not match the pending work item because it is queued with NULL data but dequeued with the connection pointer.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/380e67b1794a9a281a0cb592b4e62077fbd0c8ca
- https://git.kernel.org/stable/c/a55618c0f4cead9e59c63f5ee030d393fd70d861
- https://git.kernel.org/stable/c/a921957d39290143629eb38c4f74b9bef8035d0a
- https://git.kernel.org/stable/c/bfea6091e0fffb270c20e74384b660910277eb6c
- https://git.kernel.org/stable/c/d9019210c8c30d40eb20094274cc647e352f48f7