CVE-2026-78408

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.

Scoring

Severity
HIGH
CVSS base score
7.9
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H
EPSS probability
0.11%
CWE
CWE-775
Published
2026-09-02
Last modified
2026-09-05

Affected products

Weakness type

Related vulnerabilities

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