CVE-2026-80757 selinux: reject a class permission count below its inherited common
A local attacker with high privileges can trigger an out-of-bounds heap write in the Linux kernel SELinux subsystem, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80757?
CVE-2026-80757 is a memory corruption vulnerability in Linux, published on 3 Sep 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:
selinux: reject a class permission count below its inherited common
security_get_permissions() maps an inherited common's permissions into an array sized by the class's own permissions.nprim, but class_read() takes that nprim verbatim from the policy image and never checks that it covers the common. A class that inherits a common of N permissions while declaring a smaller nprim is accepted, and on load the common's permissions are written past the class-sized array -- an out-of-bounds heap write.
Reject a class whose permission count is below its inherited common's. Well-formed policies, where the class count already includes the inherited permissions, are unaffected.
Which versions are affected by CVE-2026-80757?
How do I fix CVE-2026-80757?
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-2026-80757 being exploited?
There is no known exploitation of CVE-2026-80757 in the wild and no public exploit code.
Sources
Also known as AZL-99039, BELL-CVE-2026-80757, DEBIAN-CVE-2026-80757, GHSA-q3g3-69gg-f28j, UBUNTU-CVE-2026-80757.