Vulnerabilities

Vulnerability · CVE-2025-40122

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unc

Published Nov 12, 2025 · catalog updated May 11, 2026 · Linux Linux

Open the advisory

Exploitation likelihood is not on this record for CVE-2025-40122. A missing EPSS score is not a low risk. Compare Linux Linux with the linked advisory before you change production.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
None0.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Not in the current FIRST EPSS dataset
Remediation
Version ranges on file
Affected products
vendor Linux Linux ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unchecked MSR access error" is seen when accessing IA32_PMC_x_CFG_B MSRs. [ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30) [ 55.611280] Call Trace: [ 55.611282] [ 55.611284] ? intel_pmu_config_acr+0x87/0x160 [ 55.611289] intel_pmu_enable_acr+0x6d/0x80 [ 55.611291] intel_pmu_enable_event+0xce/0x460 [ 55.611293] x86_pmu_star

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.

  • vendor Linux Linux ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1

How to fix CVE-2025-40122

  • Recommended remediation

    Affected version ranges suggest a fixed boundary. Verify against the vendor advisory for your release.

  • Official advisories

What to do

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

Should you patch?

Exploitation likelihood is not on this record for CVE-2025-40122. A missing EPSS score is not a low risk. Compare Linux Linux with the linked advisory before you change production.

Which versions are affected?

Compare what you have installed with Linux Linux ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1 ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS is absent from the current FIRST dataset. 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. Nov 12, 2025 · EUVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unchecked MSR access error" is seen when accessing IA32_PMC_x_CFG_B MSRs. [ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30) [

  2. May 11, 2026 · EUVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unchecked MSR access error" is seen when accessing IA32_PMC_x_CFG_B MSRs. [ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30) [

Sources

  • EUVDVulnerability recordEUVD-2025-124961

    In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unchecked MSR access error" is seen when accessing IA32_PMC_x_CFG_B MSRs. [ 55.611268] unchecked MSR ac

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.