Util linux: [Local Privilege Escalation via LIBMOUNT_FORCE_MOUNT2 Environment Variable - nosuid/noexec Bypass in SUID mount(8)] (CVE-2026-53614)

CVE-2026-53614 is a local privilege escalation vulnerability in the util-linux package's mount(8) command. The flaw arises from the LIBMOUNT_FORCE_MOUNT2 environment variable enabling bypass of nosuid and noexec mount options when mount(8) is executed with SUID privileges. This allows a local attacker with low privileges to escalate to higher privileges by exploiting this environment variable. The vulnerability affects multiple specific Ubuntu package versions of util-linux prior to the patched releases. The CVSS 3.1 vector is AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H, reflecting local attack vector, high attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. Ubuntu has released patches addressing this issue as documented in their security notice USN-8702-1.

Successful exploitation allows a local attacker to bypass nosuid and noexec mount options in the SUID mount(8) utility, resulting in full compromise of confidentiality, integrity, and availability on affected systems. This enables privilege escalation from low-privileged users to root or equivalent high privileges.

A patch is available and should be applied promptly. Ubuntu has released fixed versions of util-linux as detailed in security notice USN-8702-1. Users should upgrade to the patched versions to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.