Util-linux: util-linux: nsenter --join-cgroup leaks root cgroup migration authority
Historical advisory recorded 5 Nov 2026 03:54:02 UTC. Read the latest advisory.
cve-program · CVE-2026-78408
PublishedThe nsenter --join-cgroup option opens the target cgroup.procs file as root and leaves that file descriptor open across later namespace and credential changes and across execve(). Because the kernel checks later cgroup migrations using the credentials from the original open, a program run in an attacker-controlled target can inherit root's ability to move host processes between cgroups. After a privileged operator uses --join-cgroup against that target, an unprivileged user can migrate and terminate unrelated root processes.
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cve-program · CVE-2026-78408
PublishedUtil-linux: util-linux: nsenter --join-cgroup leaks root cgroup migration authority
The nsenter --join-cgroup option opens the target cgroup.procs file as root and leaves that file descriptor open across later namespace and credential changes and across execve(). Because the kernel checks later cgroup migrations using the credentials from the original open, a program run in an attacker-controlled target can inherit root's ability to move host processes between cgroups. After a privileged operator uses --join-cgroup against that target, an unprivileged user can migrate and terminate unrelated root processes.
- Source published
- 2 Sep 2026 15:05:33 UTC
- Source modified
- 5 Nov 2026 02:43:52 UTC
- Saved here
- 5 Nov 2026 03:54:02 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 7.9 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H