CVE-2026-99065

Kernel crash via unchecked cpuset parent traversal

Published Oct 23, 2026 · Updated Oct 23, 2026

A cpuset race in Linux 6.16 allows attackers to trigger a kernel crash during task placement concurrent with CPU offlining. In kernel/cgroup/cpuset.c, guarantee_active_cpus() follows parent cpusets without checking for NULL after cpu_active_mask changes but before effective_cpus is synchronized. Triggering requires that timing window; the published report does not establish minimum attacker privileges or a network trigger.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A cpuset race in Linux 6.16 allows attackers to trigger a kernel crash during task placement concurrent with CPU offlining. In kernel/cgroup/cpuset.c, guarantee_active_cpus() follows parent cpusets without checking for NULL after cpu_active_mask changes but before effective_cpus is synchronized. Triggering requires that timing window; the published report does not establish minimum attacker privileges or a network trigger.

The record

CVE
CVE-2026-99065
Published
Oct 23, 2026
Updated
Oct 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 23, 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=7a0aabd9ce697fc581ec691b21f748050fbcf004 <23b1ab15ca91f2cffaf149d9bb0fafeb700c7db2
  3. Affected versionversion=7a0aabd9ce697fc581ec691b21f748050fbcf004 <8d88d3221204fbb1b6dc2c0f2f2181fe49126639
  4. Affected versionversion=7a0aabd9ce697fc581ec691b21f748050fbcf004 <a21c255159bfe0034740292e10d2e258feeeb10d

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.16; version=7a0aabd9ce697fc581ec691b21f748050fbcf004 <23b1ab15ca91f2cffaf149d9bb0fafeb700c7db2; version=7a0aabd9ce697fc581ec691b21f748050fbcf004 <8d88d3221204fbb1b6dc2c0f2f2181fe49126639; version=7a0aabd9ce697fc581ec691b21f748050fbcf004 <a21c255159bfe0034740292e10d2e258feeeb10d

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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