SB20260425130 - Use-after-free in Linux kernel mm
Published: April 25, 2026
Security Bulletin ID
SB20260425130
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-31586)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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
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().
Remediation
Install update from vendor's website.