CVE-2026-43439

A flaw was found in the Linux kernel's cgroup functionality, which manages and allocates system resources. A race condition, a situation where multiple operations occur simultaneously and interfere with each other, exists during task migration and iteration. This can lead to an incomplete display of active tasks within a control group. In severe cases, this vulnerability could cause system instability, including crashes or infinite loops, potentially resulting in a Denial of Service (DoS).

A race in cgroup task migration can make css_task_iter advance relative to the wrong list when a task is moved from cset tasks to cset mg_tasks while cgroup.procs is being read. This can cause remaining tasks to be skipped during iteration, so user space may observe an incomplete task list for the cgroup. For the CVSS the PR:L is used because practical triggering requires a local process with permission to read and race cgroup.procs updates or with delegated control over task migration between cgroups. The issue is not network reachable and is triggered through local cgroup control plane operations rather than packet traffic.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.