Red Hat Security Advisory: util-linux security update

Fixed packages 24

Vulnerabilities 9

• High 8.0
  CVE-2026-53615

  util-linux libblkid DOS extended-partition overflow produces invalid partition metadata

  util-linux is a random collection of Linux utilities. Before util-linux 2.41.4, `parse_dos_extended()` in `libblkid/src/partitions/dos.c` computes an extended-partition start sector with 32-bit addition and does not apply the extended-area bounds checks to th…

  util-linux util-linux util-linux util-linux Linux Debian Ubuntu Azure Linux
  Oct 14, 2026
• High 7.9
  CVE-2026-78408

  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 th…

  Red Hat Red Hat Enterprise Linux 9 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 7 Linux Debian Ubuntu Azure Linux Alpine
  Sep 2, 2026
• High 7.8
  CVE-2026-76642

  util-linux libmount Privilege Escalation via Failed Mount Helper

  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.owne…

  util-linux util-linux util-linux util-linux Linux Debian Ubuntu Azure Linux Alpine
  Sep 3, 2026
• High 7.8
  CVE-2026-78410

  Util-linux: util-linux: restricted bind mounts do not pin the source, allowing x-mount.owner/group/mode redirection

  A flaw was found in util-linux. Restricted bind mounts take the source path from fstab but do not pin that source before the privileged mount. A local unprivileged user who can replace the authorized source or a writable ancestor can redirect SUID mount(8) to…

  Red Hat Red Hat Enterprise Linux 9 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 7 Linux Debian Ubuntu Azure Linux Alpine
  Sep 2, 2026
• High 7.0
  CVE-2026-53612

  util-linux mount hook_owner TOCTOU allows local privilege escalation

  util-linux is a random collection of Linux utilities. In util-linux 2.39 through 2.41.4 and 2.42 through 2.42.1, the SUID `mount` utility's `hook_owner.c` post-mount hook performs path-based `chmod()` and `lchown()` operations on a previously validated mount …

  util-linux util-linux util-linux util-linux Linux Debian Ubuntu Azure Linux Alpine
  Oct 14, 2026
• High 7.0
  CVE-2026-53613 Public exploit

  util-linux mount target TOCTOU allows local privilege escalation

  util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before…

  util-linux util-linux util-linux util-linux Linux Debian Ubuntu Azure Linux Alpine
  Oct 14, 2026
• High 7.0
  CVE-2026-53614

  util-linux LIBMOUNT_FORCE_MOUNT2 allows nosuid and noexec bypass

  util-linux is a random collection of Linux utilities. In util-linux 2.39.1 through 2.41.4 and 2.42 through 2.42.1, the SUID `mount` utility reads the attacker-controlled `LIBMOUNT_FORCE_MOUNT2` environment variable with `getenv()`, allowing a local low-privil…

  util-linux util-linux util-linux util-linux Linux Debian Ubuntu Azure Linux Alpine
  Oct 14, 2026
• Medium 6.8
  CVE-2026-13595

  Util-linux: util-linux: heap use-after-free in libblkid nested partition probing

  A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition ad…

  Red Hat Red Hat Enterprise Linux 9 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 7 Linux Debian Ubuntu Azure Linux
  Jun 29, 2026
• Medium 4.7
  CVE-2026-27456

  util-linux: TOCTOU Race Condition in util-linux mount(8) - Loop Device Setup

  util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates …

  util-linux util-linux util-linux util-linux Linux Debian Ubuntu Azure Linux Alpine
  Apr 3, 2026

References

• article
  https://access.redhat.com/security/updates/classification/#important
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2454956
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2494101
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2519646
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2519647
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2519648
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2521999
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2522497
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2522684
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2552551
• advisory
  https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_93461.json
• report
  https://access.redhat.com/security/cve/CVE-2026-13595
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-13595
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-13595
• article
  https://github.com/util-linux/util-linux/commit/c0186f14fbdb02f64c8e0ba701ce727ea764ff4c
• report
  https://access.redhat.com/security/cve/CVE-2026-27456
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-27456
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-27456
• article
  https://github.com/util-linux/util-linux/commit/5e390467b26a3cf3fecc04e1a0d482dff3162fc4
• article
  https://github.com/util-linux/util-linux/releases/tag/v2.41.4
• article
  https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g
• report
  https://access.redhat.com/security/cve/CVE-2026-53612
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-53612
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-53612
• article
  https://github.com/util-linux/util-linux/security/advisories/GHSA-g8wm-75wr-g2vh
• report
  https://access.redhat.com/security/cve/CVE-2026-53613
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-53613
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-53613
• article
  https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g
• report
  https://access.redhat.com/security/cve/CVE-2026-53614
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-53614
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-53614
• article
  https://github.com/util-linux/util-linux/security/advisories/GHSA-67r7-8m5w-22wx
• report
  https://access.redhat.com/security/cve/CVE-2026-53615
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-53615
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-53615
• article
  https://github.com/util-linux/util-linux/commit/05c2dbadf34cc74192287f377904afaaf4061623
• article
  https://github.com/util-linux/util-linux/commit/a2d858176b609ab5b8535021a3af9cd302d23d31
• article
  https://github.com/util-linux/util-linux/commit/e9d544d013267ea86b70ee8ff78abd280e6641af