CVE-2026-78408

HIGH

MEDIUM Priority: 0.02 BB Relevance: 31/100

Published: 2026-09-02 Modified: 2026-10-30 First seen: 2026-10-30 Status: active

Attack Surface

Low Complexity Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Local

AC: Low

PR: Low

UI: Required

S: Changed

C: None

I: High

A: High

Description

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.