# CVE-2026-98772: USB: serial: fix port tear down use-after-free

> A race condition in Linux kernel USB serial drivers allows attackers to trigger a use-after-free, potentially leading to code execution or system crashes.

- **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:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-108776, BELL-CVE-2026-98772, DEBIAN-CVE-2026-98772, GHSA-39q3-pw49-mrvf, UBUNTU-CVE-2026-98772

## What is CVE-2026-98772?

CVE-2026-98772 is an use after free vulnerability in Linux, published on 18 Oct 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: serial: fix port tear down use-after-free

Some drivers for multiport devices access port driver data from
completion handlers of shared URBs submitted at attach() or first open()
and stopped at disconnect() or last close(), respectively.

A simple NULL check before accessing the driver data makes sure that a
port state container has at least been allocated, but a completion
handler can still race with port tear down.

Reorder the disconnect handling so that ports are not deregistered (and
their driver data freed) until after all ports have been hung up and the
driver disconnect() callback has run so that all I/O has been stopped.

## Which versions are affected by CVE-2026-98772?


## How do I fix CVE-2026-98772?

Apply the vendor's patch.

## Is CVE-2026-98772 being exploited?

There is no known exploitation of CVE-2026-98772 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98772 and fix it if it is affected.

What it is: CVE-2026-98772 is an use after free vulnerability in Linux, published on 18 Oct 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-2026-98772 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-2026-98772/ (Markdown: https://insights.sbomify.com/CVE-2026-98772/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98772
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98772
- OSV: https://osv.dev/vulnerability/CVE-2026-98772

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98772/
Summaries are generated and may contain mistakes; the official description above is the record.