CVE-2026-34177

CRITICAL9.1EPSS 0.16%

LXD: VM lowlevel restriction bypass via raw.apparmor and raw.qemu.conf

Published: 4/10/2026Modified: 4/28/2026

Description

Canonical LXD versions 4.12 through 6.7 contain an incomplete denylist in isVMLowLevelOptionForbidden (lxd/project/limits/permissions.go), which omits raw.apparmor and raw.qemu.conf from the set of keys blocked under the restricted.virtual-machines.lowlevel=block project restriction. A remote attacker with can_edit permission on a VM instance in a restricted project can inject an AppArmor rule and a QEMU chardev configuration that bridges the LXD Unix socket into the guest VM, enabling privilege escalation to LXD cluster administrator and subsequently to host root.

Affected packages (3)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1CRITICAL9.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

References (5)