CVE-2023-53438

Medium

In the Linux kernel, the following vulnerability has been resolved: x86/MCE: Always save CS register on AMD Zen IF Poison errors The Instruction Fetch (IF) units on current AMD Zen-based systems do not guarantee a synchronous #MC is delivered for poison consumption errors. Therefore, MCG_STATUS[EIPV|RIPV] will not be set. However, the microarchitecture does guarantee that the exception is delivered within the same context. In other words, the exact rIP is not known, but the context is known to not have changed. There is no architecturally-defined method to determine this behavior. The Code Segment (CS) register is always valid on such IF unit poison errors regardless of the value of MCG_STATUS[EIPV|RIPV]. Add a quirk to save the CS register for poison consumption from the IF unit banks. This is needed to properly determine the context of the error. Otherwise, the severity grading function will assume the context is IN_KERNEL due to the m->cs value being 0 (the initialized value). This leads to unnecessary kernel panics on data poison errors due to the kernel believing the poison consumption occurred in kernel context.

Package Linux Kernel
Published 2025-09-18
Last modified 2026-01-14
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 2.6.12 and later are affected. Fixed in 6.1.53, 6.4.16, 6.5.3, 6.6 and their respective stable series.

Affected from
≥ 2.6.12
Fixed in
✓ 6.1.53 6.1.x ✓ 6.4.16 6.4.x ✓ 6.5.3 6.5.x ✓ 6.6

References

The following references provide additional information about CVE-2023-53438 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2023-53438?

    CVE-2023-53438 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.12 onward and has been patched in 6.1.53, 6.4.16, 6.5.3 and others. CVE-2023-53438 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2023-53438?

    CVE-2023-53438 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2023-53438?

    Yes — CVE-2023-53438 has been patched. Fixed versions include 6.1.53, 6.4.16, 6.5.3 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2023-53438 actively exploited?

    No — CVE-2023-53438 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.