CVE-2026-23269 apparmor: validate DFA start states are in bounds in unpack_pdb
An out-of-bounds read in the Linux kernel AppArmor module allows attackers to cause a denial of service or disclose sensitive memory information.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23269?
CVE-2026-23269 is a high-severity memory corruption vulnerability in Linux kernel, published on 18 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
apparmor: validate DFA start states are in bounds in unpack_pdb
Start states are read from untrusted data and used as indexes into the DFA state tables. The aa_dfa_next() function call in unpack_pdb() will access dfa->tables[YYTD_ID_BASE][start], and if the start state exceeds the number of states in the DFA, this results in an out-of-bound read.
================================================================== BUG: KASAN: slab-out-of-bounds in aa_dfa_next+0x2a1/0x360 Read of size 4 at addr ffff88811956fb90 by task su/1097 ...
Reject policies with out-of-bounds start states during unpacking to prevent the issue.
Weakness: CWE-125
Which versions are affected by CVE-2026-23269?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23269?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-23269 being exploited?
There is no known exploitation of CVE-2026-23269 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-80082, BELL-CVE-2026-23269, DEBIAN-CVE-2026-23269, GHSA-cq3w-r62m-5jvq, UBUNTU-CVE-2026-23269.