# CVE-2026-23443: ACPI: processor: Fix previous acpi_processor_errata_piix4() fix

> A use-after-free vulnerability in the Linux kernel ACPI processor driver allows attackers to cause a denial of service via improper device pointer handling.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 3 Apr 2026
- **Updated:** 11 May 2026
- **Also known as:** AZL-110417, BELL-CVE-2026-23443, DEBIAN-CVE-2026-23443, GHSA-gh6m-4cqq-86hr, UBUNTU-CVE-2026-23443

## What is CVE-2026-23443?

CVE-2026-23443 is a medium-severity use after free vulnerability in Linux kernel, published on 3 Apr 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:

ACPI: processor: Fix previous acpi_processor_errata_piix4() fix

After commi f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference
in acpi_processor_errata_piix4()"), device pointers may be dereferenced
after dropping references to the device objects pointed to by them,
which may cause a use-after-free to occur.

Moreover, debug messages about enabling the errata may be printed
if the errata flags corresponding to them are unset.

Address all of these issues by moving message printing to the points
in the code where the errata flags are set.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-23443?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23443?

Apply the vendor's patch.

## Is CVE-2026-23443 being exploited?

There is no known exploitation of CVE-2026-23443 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23443 and fix it if it is affected.

What it is: CVE-2026-23443 is a medium-severity use after free vulnerability in Linux kernel, published on 3 Apr 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-2026-23443 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-23443/ (Markdown: https://insights.sbomify.com/CVE-2026-23443/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23443
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23443
- OSV: https://osv.dev/vulnerability/CVE-2026-23443

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23443/
Summaries are generated and may contain mistakes; the official description above is the record.