CVE-2026-13595: Util-linux: util-linux: heap use-after-free in libblkid nested partition probing

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-29 · updated 2026-10-30
Weakness: CWE-416

Description

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 additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to limited information disclosure or denial of service.

Affected products

util-linux: before 2.42.2 — fixed in 2.42.2
Red Hat Enterprise Linux: 7.0, 8.0, 9.0, 10.0 (and their updates)
RedHat Hardened Images: all versions
Red Hat OpenShift Container Platform 4.18: from 4.0 through 4.22.1
Red Hat OpenShift Container Platform 4.18: all versions
Red Hat Enterprise Linux 10: all versions
Red Hat Enterprise Linux 7: all versions
Red Hat Enterprise Linux 8: all versions
Red Hat Enterprise Linux 9: all versions
Red Hat Hardened Images: all versions — fixed in 2.42.2-1.hum1
Red Hat OpenShift Container Platform 5: all versions

How to fix

Upgrade to a fixed version: util-linux 2.42.2; Red Hat Hardened Images 2.42.2-1.hum1. Check the vendor advisory for mitigations.

References

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