Link Following Affecting util-linux package, versions <2.42.3-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.15% (4th percentile)

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  • Snyk IDSNYK-ALPINE324-UTILLINUX-19533435
  • published5 Sept 2026
  • disclosed2 Sept 2026

Introduced: 2 Sep 2026

CVE-2026-78409  (opens in a new tab)
CWE-59  (opens in a new tab)

How to fix?

Upgrade Alpine:3.24 util-linux to version 2.42.3-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream util-linux package and not the util-linux package as distributed by Alpine. See How to fix? for Alpine:3.24 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1