# CVE-2026-76642: util-linux libmount Privilege Escalation via Failed Mount Helper

CVE-2026-76642 is fixed in 32 products on 1 platform, first by RHSA-2026:93461, released September 2, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-76642
- Priority: High
- CVSS: 8.0 (Moderate)
- EPSS: 0.0022
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 2, 2026
- Weakness: Detection of Error Condition Without Action
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-76642

## Description

util-linux versions through 2.41.5 and 2.42.2 fail to check mount helper exit status before running post-mount hooks, allowing unprivileged users to execute privileged operations on pre-existing filesystems. Attackers can exploit X-mount.idmap or X-mount.owner hooks to clone filesystems with inherited suid bits or modify target inode permissions after a helper fails, achieving privilege escalation.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libblkid Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libblkid almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libblkid ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libblkid-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libblkid-devel Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libblkid-devel almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libblkid-devel ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libfdisk Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libfdisk almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libfdisk ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libfdisk-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libfdisk-devel Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libfdisk-devel almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libfdisk-devel ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | liblastlog2 Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | liblastlog2-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | liblastlog2-devel Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libmount Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libmount almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libmount ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libmount-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libmount-devel Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libmount-devel almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libmount-devel ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libsmartcols Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libsmartcols almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libsmartcols ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libsmartcols-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libsmartcols-devel Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libsmartcols-devel almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libsmartcols-devel ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libuuid Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libuuid almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libuuid ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libuuid-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libuuid-devel Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | libuuid-devel almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | libuuid-devel ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | python-libmount opensuse-leap 16.0 | 2.41.1-160000.5.1 | [OPENSUSE-SU-2026:21905-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21905-1.md) | Sep 22, 2026 |
| Linux | python-libmount sles 16.0 | 2.41.1-160000.5.1 | [SUSE-SU-2026:23870-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23870-1.md) | Sep 22, 2026 |
| Linux | python3-libmount Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | python3-libmount almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | python3-libmount ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | python3-libmount-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux Debian 14 | 2.42.3-1 | [DEBIAN-CVE-2026-76642](https://patchblox.com/security/data/fix/linux/debian-cve-2026-76642.md) | Sep 17, 2026 |
| Linux | util-linux Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux RHEL 10 | 2.40.2-18.el10_2.20 | [RHSA-2026:93461](https://patchblox.com/security/data/fix/linux/rhsa-2026-93461.md) | Sep 2, 2026 |
| Linux | util-linux almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | util-linux ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | util-linux opensuse-leap 16.0 | 2.41.1-160000.5.1 | [OPENSUSE-SU-2026:21905-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21905-1.md) | Sep 22, 2026 |
| Linux | util-linux rocky 10 | 0:2.40.2-18.el10_2.20 | [RLSA-2026:93461](https://patchblox.com/security/data/fix/linux/rlsa-2026-93461.md) | Nov 7, 2026 |
| Linux | util-linux sles 16.0 | 2.41.1-160000.5.1 | [SUSE-SU-2026:23870-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23870-1.md) | Sep 22, 2026 |
| Linux | util-linux-core Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-core almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | util-linux-core ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | util-linux-core-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-debugsource Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-i18n Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-script Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-script-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | util-linux-systemd opensuse-leap 16.0 | 2.41.1-160000.5.1 | [OPENSUSE-SU-2026:21905-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21905-1.md) | Sep 22, 2026 |
| Linux | util-linux-systemd sles 16.0 | 2.41.1-160000.5.1 | [SUSE-SU-2026:23870-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23870-1.md) | Sep 22, 2026 |
| Linux | uuidd Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |
| Linux | uuidd almalinux 10 | 2.40.2-18.el10_2.20 | [ALSA-2026:93461](https://patchblox.com/security/data/fix/linux/alsa-2026-93461.md) | Nov 7, 2026 |
| Linux | uuidd ol 10 | 0:2.40.2-18.0.1.el10_2.20 | [ELSA-2026-93461](https://patchblox.com/security/data/fix/linux/elsa-2026-93461.md) | Nov 7, 2026 |
| Linux | uuidd-debuginfo Fedora 43 | 2.41.6-1.fc43 | [FEDORA-2026-B7A077A212](https://patchblox.com/security/data/fix/linux/fedora-2026-b7a077a212.md) | Nov 7, 2026 |

---

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