# CVE-2026-98748: serial: 8250_bcm7271: fix use-after-free in brcmuart_remove()

> A use-after-free in the BCM7271 serial driver allows local attackers to execute code or crash the system when hardware flow control is enabled.

- **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-109419, BELL-CVE-2026-98748, DEBIAN-CVE-2026-98748, GHSA-7g75-q55x-6r4j, UBUNTU-CVE-2026-98748

## What is CVE-2026-98748?

CVE-2026-98748 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:

serial: 8250_bcm7271: fix use-after-free in brcmuart_remove()

brcmuart_handle_irq() starts priv->hrt to work around a receive-timeout
quirk of the 8250 core when hardware flow control is enabled; the timer
callback brcmuart_hrtimer_func() dereferences priv.

brcmuart_remove() cancels the hrtimer before it unregisters the port, so
a receive-timeout interrupt that arrives in between re-arms the timer.
After devm frees priv, the callback runs on freed memory.

Unregister the port before cancelling the hrtimer.
serial8250_unregister_port() shuts the port down and frees its IRQ, so
brcmuart_handle_irq() can no longer restart the timer, and the final
hrtimer_cancel() drains any timer that was armed before or during the
unregister.

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

## Which versions are affected by CVE-2026-98748?


## How do I fix CVE-2026-98748?

Apply the vendor's patch.

## Is CVE-2026-98748 being exploited?

There is no known exploitation of CVE-2026-98748 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98748 and fix it if it is affected.

What it is: CVE-2026-98748 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-2026-98748 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-2026-98748/ (Markdown: https://insights.sbomify.com/CVE-2026-98748/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98748
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98748
- OSV: https://osv.dev/vulnerability/CVE-2026-98748

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98748/
Summaries are generated and may contain mistakes; the official description above is the record.