CPU isolation bypass via unchecked partition overlap
Published Oct 18, 2026 · Updated Oct 18, 2026
CPU isolation bypass in Linux 6.16 cpuset allows local users to assign the same exclusive CPUs to overlapping cgroup partitions. In remote_partition_enable(), a CPU-mask conflict produces only a warning instead of rejecting a descendant partition beneath a local partition through an intermediate member cgroup. Triggering requires administrative control of cgroup v2 cpuset partitions; the documented result is conflicting CPU ownership, not demonstrated code execution or a crash.
Summary
What happened
CPU isolation bypass in Linux 6.16 cpuset allows local users to assign the same exclusive CPUs to overlapping cgroup partitions. In remote_partition_enable(), a CPU-mask conflict produces only a warning instead of rejecting a descendant partition beneath a local partition through an intermediate member cgroup. Triggering requires administrative control of cgroup v2 cpuset partitions; the documented result is conflicting CPU ownership, not demonstrated code execution or a crash.
The record
- CVE
- CVE-2026-98542
- Published
- Oct 18, 2026
- Updated
- Oct 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Oct 18, 2026CVE publishedPublication date reported by the CVE source.
- Oct 18, 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.
- Affected versionversion=6.16
- Affected versionversion=86888c7bd117c29eab169c37e5f6bbbf583da983 <0751ab665cb3dcdac224b002565f2e28461740d5
- Affected versionversion=86888c7bd117c29eab169c37e5f6bbbf583da983 <241e67b60308cdce25bba66616a109759edd1d40
- Affected versionversion=86888c7bd117c29eab169c37e5f6bbbf583da983 <31c88350b7dd1522792f726f79607f31bb55c50f
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
- Upstream cpuset partition-overlap reproducerproof of concept · demonstrated
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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