SB2026040169 - Multiple vulnerabilities in Util-linux

Description

This security bulletin contains information about 2 vulnerabilities.

1) Race condition (CVE-ID: CVE-2026-27456)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 8.2 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N]

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to a race condition in the SUID binary /usr/bin/mount from util-linux. A local user can mount any root-owned file or block device that contains a valid filesystem, gaining full read access to its contents.

The mounted filesystem has MS_SECURE flags applied (nosuid, nodev, noexec), which prevents execution of SUID binaries but does not restrict reading data.

2) Integer overflow (CVE-ID: CVE-2026-53615)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: 7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service and overwrite critical disk structures.

The vulnerability exists due to integer overflow or wraparound in parse_dos_extended() in libblkid/src/partitions/dos.c when parsing a crafted disk image or removable media containing malicious EBR partition entries. A remote attacker can provide a specially crafted disk image or removable media to cause a denial of service and overwrite critical disk structures.

The issue can cause a wrapped partition start value to be registered as sector 0, which may lead downstream consumers to treat the MBR as a valid partition.

Remediation

Install update from vendor's website.

References

• https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g
• https://github.com/util-linux/util-linux/security/advisories/GHSA-h4rw-gv36-wmp5