{"affected":[{"defaultStatus":"affected","ecosystem":"https://catalog.redhat.com/software/containers/","packageName":"util-linux-main","product":"Red Hat Hardened Images","source":"CNA: redhat","vendor":"Red Hat","versions":[{"lessThan":"*","status":"unaffected","version":"2.42.2-3.4.hum1","versionType":"rpm"}]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"util-linux","product":"Red Hat Enterprise Linux 10","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"util-linux","product":"Red Hat Enterprise Linux 7","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"util-linux","product":"Red Hat Enterprise Linux 8","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"rhel8/flatpak-runtime","product":"Red Hat Enterprise Linux 9","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"rhel8/flatpak-sdk","product":"Red Hat Enterprise Linux 9","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"util-linux","product":"Red Hat Enterprise Linux 9","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"openshift/ose-rhel-coreos-8","product":"Red Hat OpenShift Container Platform 4","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"openshift/ose-rhel-coreos-9","product":"Red Hat OpenShift Container Platform 4","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"openshift/ose-rhel-coreos-9","product":"Red Hat OpenShift Container Platform 5","source":"CNA: redhat","vendor":"Red Hat","versions":[]}],"cveId":"CVE-2026-78409","cwes":["CWE-59"],"description":"The X-mount.subdir option uses a detached-tree fast path on Linux 6.15 and later and passes the configured subdirectory to open_tree() with AT_SYMLINK_NOFOLLOW. That flag does not stop intermediate symlink traversal or keep resolution inside the newly mounted filesystem. A local unprivileged user with an fstab-authorized X-mount.subdir entry can attach a host path at the intended mountpoint.","epss":{"date":"2026-11-04","percentile":0.08674,"score":0.00189},"exploits":[{"kind":"exploit","source":"ADP: CISA-ADP","url":"https://github.com/util-linux/util-linux/security/advisories/GHSA-8f2p-47x3-43mv"}],"kev":null,"metrics":[{"score":7,"severity":"high","source":"CNA: redhat","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}],"modifiedAt":1793835456374,"publishedAt":1788361907184,"references":[{"source":"CNA: redhat","tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:63162"},{"source":"CNA: redhat","tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-78409"},{"source":"CNA: redhat","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2522607"},{"source":"CNA: redhat","tags":[],"url":"https://github.com/util-linux/util-linux/security/advisories/GHSA-8f2p-47x3-43mv"},{"source":"ADP: CISA-ADP","tags":["exploit"],"url":"https://github.com/util-linux/util-linux/security/advisories/GHSA-8f2p-47x3-43mv"}],"remediation":[{"kind":"workaround","source":"CNA: redhat","text":"Upgrade to util-linux v2.41.6, v2.42.3, or later. Until a fix is applied, do not allow unprivileged /etc/fstab entries that specify X-mount.subdir."}],"revision":"1c979bbd1e5bd31d926165435eb560d76e5dbd4559dc625c263090ad0f724acd","sources":[{"modifiedAt":1793835456374,"name":"CNA: redhat","retrievedAt":1793837348092,"url":"https://www.cve.org/CVERecord?id=CVE-2026-78409"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793837358996,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-78409"}],"ssvc":{"assessedAt":1788362946011,"automatable":"no","exploitation":"poc","source":"ADP: CISA-ADP","technicalImpact":"total"},"status":"published","title":"Util-linux: util-linux: x-mount.subdir detached-tree resolution can escape via intermediate symlinks","updatedAt":1793837358996}