# CVE-2026-98752: tty: port: fix tty_port_tty_vhangup() race

> A race condition in the Linux kernel tty port hangup logic can lead to use-after-free and NULL pointer dereferences, potentially allowing local attackers to execute code or cause a denial of service.

- **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-109184, BELL-CVE-2026-98752, DEBIAN-CVE-2026-98752, GHSA-2697-8gj7-2gh6, UBUNTU-CVE-2026-98752

## What is CVE-2026-98752?

CVE-2026-98752 is a 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:

tty: port: fix tty_port_tty_vhangup() race

Drivers rely on tty_port_tty_vhangup() to synchronously hang up their
ports before tearing down resources as part of deregistration (e.g. on
physical disconnect).

If tty_port_tty_vhangup() races with another hangup it may however
return before the port has been shut down. This is in turn can lead to
use-after-free and NULL-pointer dereferences in racing ioctls (including
a synchronous hangup) and in processing of racing asynchronous hangups
(carrier loss).

Add the missing serialisation to tty_port_tty_vhangup() and
tty_port_hangup() so that the former does not return until the port has
been shut down also when there is a racing hangup.

Note that serial core does not use tty_port_hangup(), but it already
holds the port mutex when clearing port->tty and shutting down the port
in uart_hangup().

## Which versions are affected by CVE-2026-98752?


## How do I fix CVE-2026-98752?

Apply the vendor's patch.

## Is CVE-2026-98752 being exploited?

There is no known exploitation of CVE-2026-98752 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98752 and fix it if it is affected.

What it is: CVE-2026-98752 is a 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-2026-98752 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-2026-98752/ (Markdown: https://insights.sbomify.com/CVE-2026-98752/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98752
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98752
- OSV: https://osv.dev/vulnerability/CVE-2026-98752

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98752/
Summaries are generated and may contain mistakes; the official description above is the record.