# CVE-2026-74652: serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ

> A use-after-free vulnerability in the Linux kernel's amba-pl011 serial driver allows attackers to potentially execute code or cause a denial of service via RS485 timer handling.

- **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:** 22 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** BELL-CVE-2026-74652, DEBIAN-CVE-2026-74652, GHSA-9x5x-pxv9-g7vg, UBUNTU-CVE-2026-74652

## What is CVE-2026-74652?

CVE-2026-74652 is a high-severity use after free vulnerability in Linux, published on 22 Aug 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: amba-pl011: cancel RS485 hrtimers after freeing IRQ

The RS485 trigger hrtimers are embedded in the devm-managed port and can
fire after it is freed. The IRQ handler can arm a timer, so free the IRQ
first and then cancel both timers.

Complete the RS485 stop without arming a timer, and cancel the timers
in remove() for the suspend-then-unbind path, where shutdown is not
called.

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

## Which versions are affected by CVE-2026-74652?


## How do I fix CVE-2026-74652?

Apply the vendor's patch.

## Is CVE-2026-74652 being exploited?

There is no known exploitation of CVE-2026-74652 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74652 and fix it if it is affected.

What it is: CVE-2026-74652 is a high-severity use after free vulnerability in Linux, published on 22 Aug 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-2026-74652 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-2026-74652/ (Markdown: https://insights.sbomify.com/CVE-2026-74652/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74652
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74652
- OSV: https://osv.dev/vulnerability/CVE-2026-74652

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74652/
Summaries are generated and may contain mistakes; the official description above is the record.