Deadlock in Linux kernel - CVE-2026-80920
Published: September 9, 2026
Vulnerability identifier: #VU148746
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2026-80920
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.
The vulnerability exists due to improper locking in io_uring CQ ring eventfd signaling when task work is queued from a waitqueue wakeup handler. A local user can submit io_uring operations that queue task work from a waitqueue wakeup handler to cause a denial of service.
The issue affects DEFER_TASKRUN rings with CQ ring eventfd signaling.
Affected software
Linux kernel
How to mitigate CVE-2026-80920
Install security update from vendor's repository.