Use-after-free in Linux kernel - CVE-2026-31586
Published: April 25, 2026
Vulnerability identifier: #VU127812
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-31586
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in cgwb_release_workfn() when releasing writeback resources and later dereferencing wb->blkcg_css after dropping its last reference. A local user can trigger the race condition to cause a denial of service.
The issue is race-dependent and can be observed as a KASAN-reported slab-use-after-free in blkcg_unpin_online().
How to mitigate CVE-2026-31586
Install security update from vendor's repository.