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Vulnerabilities

Vulnerability · CVE-2025-38733

In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowco

Published Sep 5, 2025 · catalog updated Oct 19, 2026 · Linux Linux

Check if you run it

No confirmed exploitation is on record for CVE-2025-38733. EPSS is 0.17%. Act only if a listed version of Linux Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.17%
Remediation
Version ranges on file
Affected products
cpe linux/linux kernel · vendor Linux Linux 32db401965f165f7c44447d0508097f070c8f576 <1d7864acd497cb468a998d44631f84896f885e85

In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer accesses will succeed instead of causing an exception (low address protection still applies, but covers only parts). To fix this never map the first two pages of physical memory with the identity mapping.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernel6.11
  • cpe linux/linux kernel6.17
  • vendor Linux Linux 32db401965f165f7c44447d0508097f070c8f576 <1d7864acd497cb468a998d44631f84896f885e8532db401965f165f7c44447d0508097f070c8f576 <1d7864acd497cb468a998d44631f84896f885e85

How to fix CVE-2025-38733

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-38733. EPSS is 0.17%. Act only if a listed version of Linux Linux is installed.

Which versions are affected?

Compare what you have installed with linux/linux kernel 6.11; linux/linux kernel 6.17; Linux Linux 32db401965f165f7c44447d0508097f070c8f576 <1d7864acd497cb468a998d44631f84896f885e85 32db401965f165f7c44447d0508097f070c8f576 <1d7864acd497cb468a998d44631f84896f885e85. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-476: NULL Pointer Dereference. EPSS 0.17%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 5, 2025 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer ac

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer ac

  3. Oct 19, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer ac

Sources

  • CVE.orgVulnerability recordCVE-2025-38733

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-38733

    30-day exploitation probability 0.2%

    first.org
  • EUVDVulnerability recordEUVD-2025-31556

    In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command li

    euvd.enisa.europa.eu
  • NIST NVDVulnerability recordCVE-2025-38733

    In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.