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

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

Which versions are affected by CVE-2026-23443?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23443?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

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 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-110417, BELL-CVE-2026-23443, DEBIAN-CVE-2026-23443, GHSA-gh6m-4cqq-86hr, UBUNTU-CVE-2026-23443.