{"id":"CVE-2026-98542","title":"kernel: cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict (CVE-2026-98542)","summary":"A flaw was found in the Linux kernel's cpuset subsystem, which can lead to a denial of service (DoS) or compromised resource isolation. A local user with permissions to configure control groups (cgroups) can trigger this flaw by creating a…","severity":"low","cvss":2.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L","cvssSource":"vendor","cwe":"CWE-390","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-10-18","updated":"2026-10-19","sourceUpdated":"2026-10-19T23:47:56+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98542.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98542.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98542"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2554922"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98542"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98542"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98542.mbox"},{"url":"https://git.kernel.org/stable/c/241e67b60308cdce25bba66616a109759edd1d40"},{"url":"https://git.kernel.org/stable/c/0751ab665cb3dcdac224b002565f2e28461740d5"},{"url":"https://git.kernel.org/stable/c/31c88350b7dd1522792f726f79607f31bb55c50f"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00198,"epssPercentile":0.09499,"ingestedAt":"2026-10-18T15:45:12.268Z","slug":"CVE-2026-98542","body":"## Overview\n\nA flaw was found in the Linux kernel's cpuset subsystem, which can lead to a denial of service (DoS) or compromised resource isolation. A local user with permissions to configure control groups (cgroups) can trigger this flaw by creating a remote partition that requests processor cores already allocated to an ancestor partition. Because the kernel fails to reject the conflicting request, multiple partitions can improperly claim exclusive access to the same central processing unit (CPU) cores, generating kernel warnings and causing inconsistent resource management.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-19 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98542.json)\n\n**kernel: cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict** — rated Low by Red Hat. Released 2026-10-18, updated 2026-10-19.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":13,"depthScoreParts":{"impact":12.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":225840,"id":"CVE-2026-98542","ts":1792498473849,"field":"cvss","old":null,"new":"2.3"},{"seq":225839,"id":"CVE-2026-98542","ts":1792498473849,"field":"severity","old":"none","new":"low"}]}