SB2026072110 - Use-after-free in Linux kernel apparmor



SB2026072110 - Use-after-free in Linux kernel apparmor

Published: July 21, 2026

Security Bulletin ID SB2026072110
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-63827)

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 aa_replace_profiles() during rawdata_list deduplication when processing policy replacement operations. A local user can trigger AppArmor profile replacement with crafted timing to cause a denial of service.

The issue occurs because entries can remain on the rawdata list after their profile reference count has reached zero and before deferred cleanup runs.


Remediation

Install update from vendor's website.