# CVE-2026-80777: futex/pi: Plug private futex exec() race

> A race condition in the Linux kernel futex implementation allows local attackers to exploit a memory management gap during exec() to potentially escalate privileges or execute code.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-80777, DEBIAN-CVE-2026-80777, GHSA-7pm4-4mcq-p2r3, UBUNTU-CVE-2026-80777

## What is CVE-2026-80777?

CVE-2026-80777 is a vulnerability in Linux, published on 4 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:

futex/pi: Plug private futex exec() race

The check for private futexes whether the waiter's mm, which is stored in
the futex_key and copied into the pi_state, is the same as the owner's mm
is not sufficient for exec(). exec() has a gap where the mm check fails to
give the correct answer:

  exec()
  ...
    exec_release_mm()
      futex_exec_release()
        tsk::futex::exit_state = EXITING;
        cleanup_robust_list();
1)      tsk::futex::exit_state = OK;
    ...
    old_mm = tsk::mm;
2)  tsk::mm = ->mm;

Between #1 and #2 the check for the mm is wrong as that mm is about to be
swapped out and eventually freed.

Plug this gap by:

  1) Setting tsk::futex::exit_state to FUTEX_STATE_DEAD in
     futex_exec_release()

  2) Setting tsk::futex::exit_state to FUTEX_STATE_OK after
     the mm has been switched.

From a futex point of view the task is dead after it finished the robust
list cleanup up to the point where it sets the state to OK again.

## Which versions are affected by CVE-2026-80777?


## How do I fix CVE-2026-80777?

Apply the vendor's patch.

## Is CVE-2026-80777 being exploited?

There is no known exploitation of CVE-2026-80777 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80777 and fix it if it is affected.

What it is: CVE-2026-80777 is a vulnerability in Linux, published on 4 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-2026-80777 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-2026-80777/ (Markdown: https://insights.sbomify.com/CVE-2026-80777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80777
- OSV: https://osv.dev/vulnerability/CVE-2026-80777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80777/
Summaries are generated and may contain mistakes; the official description above is the record.