Use-after-free in Linux kernel - CVE-2026-63827
Published: July 21, 2026
Vulnerability identifier: #VU138834
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-2026-63827
CWE-ID: CWE-416
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 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.
Affected software
Linux kernel
How to mitigate CVE-2026-63827
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/15fd83a1e42ede15070968806bb6c8b1a5170688
- https://git.kernel.org/stable/c/5e34fa9f6f7cd688ae153fff13139a5cf2d42339
- https://git.kernel.org/stable/c/6f060496d03e4dc560a40f73770bd08335cb7a27
- https://git.kernel.org/stable/c/a7a2890028f16e5b0af0bb005d80fcb32559cca3
- https://git.kernel.org/stable/c/c3ca2631073b2cef06824fd2bfc452ff7a1023de
- https://git.kernel.org/stable/c/ce261a20b41db522e320a41bbf1292bf85af66df