Linux Kernel EUVD-2026-32404

The primary remediation is upgrading to a patched Linux kernel release: mainline 7.1-rc1 or later, 7.0.4 or later for the 7.0.x stable series, 6.18.27 or later for 6.18.x, 6.12.86 or later for the 6.12.x LTS series, and 6.6.140 or later for the 6.6.x LTS series. Fix commits are accessible directly at git.kernel.org (see references: 17a08791d428885d00e510864283a7b839792368 and associated stable backports). If immediate patching is not feasible, a practical compensating control is to restrict access to device mapper configuration interfaces by ensuring only privileged users with explicit CAP_SYS_ADMIN capability can submit device mapper table strings - tightening udev rules, container security profiles (seccomp, AppArmor, SELinux), and avoiding granting unprivileged access to /dev/mapper. Disabling the dm-mirror module (modprobe -r dm-mirror) where mirroring is not in use eliminates the attack surface entirely, though this will disable disk mirroring functionality. Downstream distributions (RHEL, Debian, Ubuntu, SUSE) will backport the fix to their own kernel packages; check respective vendor security advisories for distribution-specific patch availability.