Util-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.
CVE-2026-78408
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-78408
Red Hat Hardened Images
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 10
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 7
Source reference: /containers/cna/affected/2/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 8
Source reference: /containers/cna/affected/3/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9
Source reference: /containers/cna/affected/4/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9
Source reference: /containers/cna/affected/5/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat Enterprise Linux 9
Source reference: /containers/cna/affected/6/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift Container Platform 4
Source reference: /containers/cna/affected/7/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Red Hat OpenShift Container Platform 4
Source reference: /containers/cna/affected/8/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"cpes": [
"cpe:/a:redhat:hummingbird:1"
],
"vendor": "Red Hat",
"product": "Red Hat Hardened Images",
"versions": [
{
"status": "unaffected",
"version": "2.42.2-3.4.hum1",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "util-linux-main",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 10",
"packageName": "util-linux",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"packageName": "util-linux",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"packageName": "util-linux",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"packageName": "rhel8/flatpak-runtime",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"packageName": "rhel8/flatpak-sdk",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"packageName": "util-linux",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/a:redhat:openshift:4"
],
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"packageName": "openshift/ose-rhel-coreos-8",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/a:redhat:openshift:4"
],
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"packageName": "openshift/ose-rhel-coreos-9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-78408
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #49333 · Revision 1
- Added to Heist Feed
- Publisher date