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{"acknowledgement": "Red Hat would like to thank Andreas Gabriel Berbescu (Independent Security Researcher) and Iv\u00e1n Redondo Plaza (Independent Security Researcher) for reporting this issue.", "bugzilla": {"description": "util-linux: util-linux: failed external mount helper still runs privileged X-mount post-hooks", "id": "2521999", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521999"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.8", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-390", "details": ["When an external mount.<type> helper runs but exits with a nonzero status, libmount still treats the helper invocation as successful and runs privileged post-mount hooks. A local unprivileged user with an /etc/fstab entry that uses the user option together with X-mount.idmap or X-mount.owner/group/mode can cause those hooks to clone or re-own the underlying filesystem after the helper fails, leading to local privilege escalation."], "mitigation": {"lang": "en:us", "value": "Upgrade to util-linux v2.41.6, v2.42.3, or later. Until a fix is applied, avoid combining the user (or users) fstab option with X-mount.idmap or X-mount.owner/group/mode on entries that invoke an external mount.<type> helper. Administrators can also remove or restrict user-mountable fstab entries that specify those X-mount.* options."}, "name": "CVE-2026-76642", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "util-linux", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "util-linux", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "util-linux", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "rhel8/flatpak-runtime", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "rhel8/flatpak-sdk", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "util-linux", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "util-linux", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-02T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-76642\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-76642\nhttps://github.com/util-linux/util-linux/security/advisories/GHSA-m25x-3hj9-m26f"], "statement": "Affected versions: util-linux v2.39 through v2.42.2. Fixed in v2.41.6 and v2.42.3.", "threat_severity": "Important"}

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