Deadlock in Linux kernel - CVE-2026-99009
Published: October 23, 2026
Vulnerability identifier: #VU157496
CSH Severity: Low
CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-99009
CWE-ID: CWE-833
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service by triggering a deadlock in Bluetooth RFCOMM processing.
The vulnerability exists due to inconsistent lock ordering in the Linux kernel Bluetooth RFCOMM subsystem when establishing an RFCOMM connection while a BR/EDR link is being authenticated. A local user can issue an RFCOMM socket connect() call from userspace to trigger circular acquisition of rfcomm_mutex and hdev->lock, potentially deadlocking Bluetooth processing.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-99009
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.115-2
linux (Debian package) - update to 6.12.115-2
External References
- https://git.kernel.org/stable/c/4dc3d5a004b8fd59f3c905631dbb18cb601b1b41
- https://git.kernel.org/stable/c/ac022970e9fb0a5f7e7d1f6c8e104c1ed924dd1c
- https://git.kernel.org/stable/c/cc7732b8549ecb6f02457edeb8db1f6d255e381c
- https://git.kernel.org/stable/c/d2206e8c78be69d21d4f5343c3e99fbaeef41cbb
- https://git.kernel.org/stable/c/f492de11b325446b0b11bc2eb86e1f546eaa61b6