CVE-2025-40122

Local denial of service via invalid ACR mask

Published Nov 12, 2025 · Updated May 11, 2026

Improper validation in Linux kernel 6.16 allows local users to interrupt service by submitting an invalid perf ACR counter mask. The off-by-one check in intel_pmu_acr_late_setup() accepts an out-of-range counter assignment and writes its bit through hw.config1 to an unsupported CFG_B MSR. Exploitation requires low-privileged local access on Intel Panther Lake hardware and affects availability without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper validation in Linux kernel 6.16 allows local users to interrupt service by submitting an invalid perf ACR counter mask. The off-by-one check in intel_pmu_acr_late_setup() accepts an out-of-range counter assignment and writes its bit through hw.config1 to an unsupported CFG_B MSR. Exploitation requires low-privileged local access on Intel Panther Lake hardware and affects availability without reported data disclosure or modification.

The record

CVE
CVE-2025-40122
Published
Nov 12, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 12, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.16
  2. Affected versionversion=ec980e4facef8110f6fce27e5b6344660117f01f <43796f30507802d93ead2dc44fc9637f34671a89
  3. Affected versionversion=ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.16; version=ec980e4facef8110f6fce27e5b6344660117f01f <43796f30507802d93ead2dc44fc9637f34671a89; version=ec980e4facef8110f6fce27e5b6344660117f01f <c6cca4213b618c92e4972919ee568f0fb87313b1

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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