# CVE-2026-80755: selinux: reject a permission value exceeding the class permission count

> A local attacker with high privileges can trigger an out-of-bounds heap write in the Linux kernel SELinux subsystem, potentially leading to privilege escalation or code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-99056, BELL-CVE-2026-80755, DEBIAN-CVE-2026-80755, GHSA-jcj2-5fhp-x66j, UBUNTU-CVE-2026-80755

## What is CVE-2026-80755?

CVE-2026-80755 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 permission value exceeding the class permission count

perm_read() bounds a permission value by SEL_VEC_MAX but never by the
nprim of the owning class or common, which is taken verbatim from the
policy image.  security_get_permissions() then writes perms[value - 1]
into an nprim-sized kcalloc() array, so a class declaring fewer
permissions than its largest permission value drives an out-of-bounds
heap write.  The top-level symbol tables are validated this way; the
nested per-class permission table is not.

Reject a permission whose value exceeds nprim, which is already set when
perm_read() runs.  Well-formed policies are unaffected.

[PM: tweak comment for line length]

## Which versions are affected by CVE-2026-80755?


## How do I fix CVE-2026-80755?

Apply the vendor's patch.

## Is CVE-2026-80755 being exploited?

There is no known exploitation of CVE-2026-80755 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80755 and fix it if it is affected.

What it is: CVE-2026-80755 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.
Exploitation: There is no known exploitation of CVE-2026-80755 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80755/ (Markdown: https://insights.sbomify.com/CVE-2026-80755/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80755
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80755
- OSV: https://osv.dev/vulnerability/CVE-2026-80755

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80755/
Summaries are generated and may contain mistakes; the official description above is the record.