# CVE-2026-80880: IB/mlx5: Properly support implicit ODP rereg_mr

> A race condition in the Linux kernel's mlx5 InfiniBand driver allows local attackers to cause denial of service or escalate privileges via implicit ODP memory registration.

- **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:** 4 Sep 2026
- **Also known as:** BELL-CVE-2026-80880, DEBIAN-CVE-2026-80880, GHSA-v3r8-hwvc-wv26, UBUNTU-CVE-2026-80880

## What is CVE-2026-80880?

CVE-2026-80880 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:

IB/mlx5: Properly support implicit ODP rereg_mr

Due to all the child mkeys in the implicit ODP configuration we cannot
change anything in place for the parent mkey. Instead the whole thing
needs to be rebuilt if any change is requested. If the user does not
specify a translation then force the implicit values which will then fall
through the logic into mlx5_ib_reg_user_mr() to allocate a completely new
MR.

Since implicit children were also touching the mr->pd, this removes
another case where the access was racy.

## Which versions are affected by CVE-2026-80880?


## How do I fix CVE-2026-80880?

Apply the vendor's patch.

## Is CVE-2026-80880 being exploited?

There is no known exploitation of CVE-2026-80880 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80880 and fix it if it is affected.

What it is: CVE-2026-80880 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-2026-80880 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-2026-80880/ (Markdown: https://insights.sbomify.com/CVE-2026-80880/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80880
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80880
- OSV: https://osv.dev/vulnerability/CVE-2026-80880

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80880/
Summaries are generated and may contain mistakes; the official description above is the record.