Vulnerability in Red Hat Enterprise Linux 10

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.9 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (7.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 7.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-78408: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78408?
CVE-2026-78408 is a high-severity vulnerability in Red Hat Enterprise Linux 10, classified under CWE-775. CVSS score: 7.9/10. Published 2026-09-02.
How severe is CVE-2026-78408?
High severity. CVSS v3 base score is 7.9 out of 10.