CVE-2026-89460

Kernel panic via uninitialized hot-added CPU counters

Published Sep 11, 2026 · Updated Sep 11, 2026

NULL-pointer dereference in Linux 6.5 s390 CPUMF allows local users to crash the kernel during per-task perf use and CPU hotplug. cpumf_pmu_add() obtains NULL from this_cpu_cfhw() because event initialization allocates counter state only for CPUs online when the event is created. The crash requires s390 CPUMF, a per-task event, and an offline CPU brought online before the monitored task is scheduled there.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL-pointer dereference in Linux 6.5 s390 CPUMF allows local users to crash the kernel during per-task perf use and CPU hotplug. cpumf_pmu_add() obtains NULL from this_cpu_cfhw() because event initialization allocates counter state only for CPUs online when the event is created. The crash requires s390 CPUMF, a per-task event, and an offline CPU brought online before the monitored task is scheduled there.

The record

CVE
CVE-2026-89460
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 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=6.5
  2. Affected versionversion=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <337bd95507a16063687cfc286ea90de5cca48c37
  3. Affected versionversion=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <71d46de9153e067c63a15f3b00e6364e1c0230f8
  4. Affected versionversion=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <777d040c2f91d8d929b4a32333dfe4102b27caea
  5. Affected versionversion=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <dcce7a06ea690d5cf46a705a9b74cf0398ac091f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=6.5; version=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <337bd95507a16063687cfc286ea90de5cca48c37; version=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <71d46de9153e067c63a15f3b00e6364e1c0230f8; version=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <777d040c2f91d8d929b4a32333dfe4102b27caea; version=9b9cf3c77e7e090b30657b3d2c288deb58dfb4f2 <dcce7a06ea690d5cf46a705a9b74cf0398ac091f

Published CVSS scores

No CVSS assessment is available in this record.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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