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Vulnerabilities

Vulnerability · CVE-2025-37936

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value.

Published May 20, 2025 · catalog updated Oct 15, 2026 · Linux Linux

Check if you run it

No confirmed exploitation is on record for CVE-2025-37936. EPSS is 0.22%. 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
High8.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.22%
Remediation
Version ranges on file
Affected products
cpe debian/debian linux · cpe linux/linux kernel · vendor Linux Linux c59a1f106f5cd4843c097069ff1bb2ad72103a67 <44ee0afc9d1e7a7c1932698de01362ed80cfc4b5

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. When generating the MSR_IA32_PEBS_ENABLE value that will be loaded on VM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE value. Consulting only the host kernel's host vs. guest masks results in running the guest with PEBS enabled even when the guest doesn't want to use PEBS. Because KVM uses perf events to proxy the guest virtual PMU, simply looking at exclude_host can't differentiate between events created by host userspace, and events created by KVM on behalf of the guest. Running the guest with PEBS unexpectedly enabled typically manifests as crashes due to a near-infinite stream of #PFs. E.g. if the guest hasn't written MSR_IA32_DS_AREA, the CPU will hit page faults on address '0' when trying to record PEBS events. The issue is most easily reproduced by running from before commit 7b100989b4f6 ("perf evlist: Remove __evlist__add_default") (after which, effectively stopped using PEBS). The userspace side of perf creates a guest-only PEBS event, which intel_guest_get_msrs() misconstrues a guest-*owned* PEBS event. Arguably, this is a userspace bug, as enabling PEBS on guest-only events simply cannot work, and userspace can kill VMs in many other ways (there is no danger to the host). However, even if this is considered to be bad userspace behavior, there's zero downside to perf/KVM restricting PEBS to guest-owned events. Note, commit 854250329c02 ("KVM: x86/pmu: Disable guest PEBS temporarily in two rare situations") fixed the case where host userspace is profiling KVM *and* userspace, but missed the case where userspace is profiling only KVM.

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 debian/debian linux11.0
  • cpe linux/linux kernel6.15
  • vendor Linux Linux c59a1f106f5cd4843c097069ff1bb2ad72103a67 <44ee0afc9d1e7a7c1932698de01362ed80cfc4b5c59a1f106f5cd4843c097069ff1bb2ad72103a67 <44ee0afc9d1e7a7c1932698de01362ed80cfc4b5

How to fix CVE-2025-37936

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-2025-37936. EPSS is 0.22%. Act only if a listed version of Linux Linux is installed.

Which versions are affected?

Compare what you have installed with debian/debian linux 11.0; linux/linux kernel 6.15; Linux Linux c59a1f106f5cd4843c097069ff1bb2ad72103a67 <44ee0afc9d1e7a7c1932698de01362ed80cfc4b5 c59a1f106f5cd4843c097069ff1bb2ad72103a67 <44ee0afc9d1e7a7c1932698de01362ed80cfc4b5. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.22%. 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. May 20, 2025 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. When generating the MSR_IA32_PEBS_ENABLE value that will be loaded on VM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE value. Consulting only the host kernel's host vs. guest masks results in running the guest with PEBS enabled eve

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. When generating the MSR_IA32_PEBS_ENABLE value that will be loaded on VM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE value. Consulting only the host kernel's host vs. guest masks results in running the guest with PEBS enabled eve

Sources

  • CVE.orgVulnerability recordCVE-2025-37936

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-37936

    30-day exploitation probability 0.2%

    first.org
  • EUVDVulnerability recordEUVD-2025-15918

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. When generating the MSR_IA32_PEBS_ENABLE value that will be loaded on VM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS

    euvd.enisa.europa.eu
  • NIST NVDVulnerability recordCVE-2025-37936

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. When generating the MSR_IA32_PEBS_ENABLE value that will be loaded on VM-Entry to a KVM guest, mask the value with the vCPU's desired PE

    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.