# CVE-2026-89737: usb: typec: thunderbolt: Disable work before freeing tbt on remove

> A use-after-free vulnerability in the Linux kernel's Thunderbolt USB Type-C driver allows local attackers to cause a system crash or potentially execute code during device removal.

- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89737, DEBIAN-CVE-2026-89737, GHSA-vj4x-g937-4233, UBUNTU-CVE-2026-89737

## What is CVE-2026-89737?

CVE-2026-89737 is an 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:

usb: typec: thunderbolt: Disable work before freeing tbt on remove

tbt_altmode_remove() drops the plug and cable references without
draining tbt->work. The work function dereferences those references,
and can also requeue itself in its error path. The VDM callbacks can
queue the same work item.

Disable and drain tbt->work before dropping the references. This waits
for an existing invocation and prevents subsequent schedule_work()
calls from queueing it during teardown.

This issue was found by an in-house static analysis tool and confirmed
by manual code review.

## Which versions are affected by CVE-2026-89737?


## How do I fix CVE-2026-89737?

Apply the vendor's patch.

## Is CVE-2026-89737 being exploited?

There is no known exploitation of CVE-2026-89737 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89737 and fix it if it is affected.

What it is: CVE-2026-89737 is an 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-2026-89737 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-2026-89737/ (Markdown: https://insights.sbomify.com/CVE-2026-89737/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89737
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89737
- OSV: https://osv.dev/vulnerability/CVE-2026-89737

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89737/
Summaries are generated and may contain mistakes; the official description above is the record.