CVE-2026-78408
util-linux nsenter Cgroup Privilege Escalation
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.
INFO
Published Date :
Sept. 2, 2026, 4:17 p.m.
Last Modified :
Sept. 2, 2026, 4:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-78408
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Limit the usage of nsenter --join-cgroup.
- Apply updates for the affected software.
- Review and restrict process cgroup access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-78408.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-78408 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2522497 | |
| https://github.com/util-linux/util-linux/security/advisories/GHSA-55fx-f4gg-cfhj |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-78408 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-78408
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-78408 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-78408 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 02, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H Added CWE CWE-775 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/78xxx/CVE-2026-78408.json">CVE-2026-78408</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-78408 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2522497 Added Reference https://github.com/util-linux/util-linux/security/advisories/GHSA-55fx-f4gg-cfhj