# CVE-2026-89510: RDMA/cxgb4: Cancel reg_work before freeing device on remove

> A use-after-free vulnerability in the Linux kernel's cxgb4 RDMA driver allows attackers to cause denial of service or execute code during device removal.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-100115, BELL-CVE-2026-89510, DEBIAN-CVE-2026-89510, GHSA-82cq-j2q5-4p5v, UBUNTU-CVE-2026-89510

## What is CVE-2026-89510?

CVE-2026-89510 is a high-severity use after free vulnerability in Linux, published on 11 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:

RDMA/cxgb4: Cancel reg_work before freeing device on remove

c4iw_uld_state_change() queues reg_work to register the RDMA device.
c4iw_remove() can free ctx->dev while this work is pending or running,
leaving c4iw_register_device() accessing the freed device.

Cancel reg_work before removing the device.  The registration work can
tear down ctx->dev when registration fails, so do not unregister or
deallocate it again in that case.

This issue was found by an in-house static analysis tool.

## Which versions are affected by CVE-2026-89510?


## How do I fix CVE-2026-89510?

Apply the vendor's patch.

## Is CVE-2026-89510 being exploited?

There is no known exploitation of CVE-2026-89510 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89510 and fix it if it is affected.

What it is: CVE-2026-89510 is a high-severity use after free vulnerability in Linux, published on 11 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-2026-89510 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-2026-89510/ (Markdown: https://insights.sbomify.com/CVE-2026-89510/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89510
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89510
- OSV: https://osv.dev/vulnerability/CVE-2026-89510

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89510/
Summaries are generated and may contain mistakes; the official description above is the record.