Review reviewHigh

CVE-2023-53205

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler We do check for target CPU == -1, but this might change at the time we are going to use it. Hold the physical target CPU in a local variable to avoid out-of-bound accesses to the cpu arrays.

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2025.09.16
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler We do check for target CPU == -1, but this might change at the time we are going to use it. Hold the physical target CPU in a local variable to avoid out-of-bound accesses to the cpu arrays.

Affected product and versions

Product
Linux Linux, linux kernel
Affected versions
>= 87e28a15c42cc592009c32a8c20e5789059027c2 < a9ccf140a2a03a0ae82be4bdfbdd17bdaea72ff5, >= 87e28a15c42cc592009c32a8c20e5789059027c2 < 86bfb18bad60fc468e5f112cbbd918462a8dd435, >= 87e28a15c42cc592009c32a8c20e5789059027c2 < dc7e0192c470a53d847c79a2796f9ac429477a26, >= 87e28a15c42cc592009c32a8c20e5789059027c2 < 0bc380beb78aa352eadbc21d934dd9606fcee808, >= 5.13, >= 5.13 < 5.15.121, >= 5.16 < 6.1.39, >= 6.2 < 6.4.4
Fixed versions
5.15.121, 6.1.39, 6.4.4

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, linux kernel and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-787