{
  "cveId": "CVE-2026-99065",
  "url": "https://patchblox.com/security/cve/CVE-2026-99065",
  "summary": "CVE-2026-99065 is fixed in linux on 1 platform by DEBIAN-CVE-2026-99065 (version 7.2.11-1), released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  cgroup/cpuset: Handle cpu hotplug race in guaran...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  cgroup/cpuset: Handle cpu hotplug race in guarantee_active_cpus()  With commit 2125c0034c5d (\u0022cgroup/cpuset: Make cpuset hotplug processing synchronous\u0022), the cpuset hotplug operation becomes synchronous. That commit also removes the code that handles race between cpuset_hotplug_work and cpu hotplug notifier with the assumption that race is now gone. Later commit 7a0aabd9ce69 (\u0022cgroup/cpuset: Always use cpu_active_mask\u0022) updates the cpuset code to always use cpu_active_mask instead of cpu_online_mask in some places including guarantee_online_cpus() which is renamed to guarantee_active_cpus() in that commit.  In the case of CPU offline operation, cpu_active_mask is updated first in sched_cpu_deactivate() to remove the offline CPU before cpuset_handle_hotplug() is called to update the effective_cpus of the affected cpusets. The cpu_online_mask is updated after that near the end of the offline operation to remove the offline CPU. As a result, the race comes back and the top cpuset may not have any active CPU leading to NULL pointer dereference during the race window when guarantee_active_cpus() is called after cpu_active_mask is updated to remove the CPU to be torn down but before cpuset_handle_hotplug() is able to properly update the effective_cpus of the top cpuset.  Fix this by adding back the NULL cs check to avoid this problem.",
  "published": "2026-10-23T13:17:30Z",
  "severity": "",
  "epss": 0.00166,
  "epssPercentile": 0.05938,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.11-1",
      "fix": "DEBIAN-CVE-2026-99065",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-99065",
      "released": "2026-10-24T13:25:57Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}