# CVE-2026-23042: idpf: fix aux device unplugging when rdma is not supported by vport

> A null pointer dereference in the Linux kernel idpf driver causes a denial of service when unplugging auxiliary devices for vports without RDMA support.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Feb 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-23042, DEBIAN-CVE-2026-23042, GHSA-8936-48hj-4rqp, UBUNTU-CVE-2026-23042

## What is CVE-2026-23042?

CVE-2026-23042 is a vulnerability in Linux, published on 4 Feb 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:

idpf: fix aux device unplugging when rdma is not supported by vport

If vport flags do not contain VIRTCHNL2_VPORT_ENABLE_RDMA, driver does not
allocate vdev_info for this vport. This leads to kernel NULL pointer
dereference in idpf_idc_vport_dev_down(), which references vdev_info for
every vport regardless.

Check, if vdev_info was ever allocated before unplugging aux device.

## Which versions are affected by CVE-2026-23042?


## How do I fix CVE-2026-23042?

Apply the vendor's patch.

## Is CVE-2026-23042 being exploited?

There is no known exploitation of CVE-2026-23042 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23042 and fix it if it is affected.

What it is: CVE-2026-23042 is a vulnerability in Linux, published on 4 Feb 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-2026-23042 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-2026-23042/ (Markdown: https://insights.sbomify.com/CVE-2026-23042/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23042
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23042
- OSV: https://osv.dev/vulnerability/CVE-2026-23042

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23042/
Summaries are generated and may contain mistakes; the official description above is the record.