CVE-2026-13595 is a use-after-free vulnerability in the libblkid library of util-linux, specifically affecting nested partition probing in BSD, Minix, Solaris x86, and UnixWare partition probers. These probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When the array is reallocated due to subsequent partition additions, the cached pointer becomes stale, resulting in a heap use-after-free read. This vulnerability can be triggered by presenting a crafted block device image, such as via USB insertion or loop-mounted disk images, as libblkid is invoked automatically by udev/udisks running as root on block-device hot-plug events. The flaw can lead to limited information disclosure or denial of service on affected Red Hat Hardened Images.

An attacker able to present a crafted block device image to a vulnerable system can trigger a heap use-after-free read in libblkid, potentially causing limited information disclosure or denial of service. The vulnerability is exploitable without user interaction due to automatic invocation by system components running as root. The CVSS v3.1 base score is 6.8 (medium severity), reflecting local attack vector with low complexity, no privileges required, no user interaction, limited confidentiality impact, no integrity impact, and high availability impact.

Red Hat has released an update for Red Hat Hardened Images including util-linux packages (version 2.42.2-1.hum1) that address this vulnerability. Users should apply the provided RPM updates to remediate the issue. For detailed update instructions, refer to the Red Hat advisory at https://access.redhat.com/errata/RHSA-2026:26573. Patch status is confirmed as an official fix available from Red Hat.