CVE-2026-34177: Canonical Lxd

Critical severity, CVSS 9.1. EPSS: 0.6% chance of exploitation in the next 30 days.

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 products

• Canonical Lxd: from 4.12, up to and including 5.0.6; from 5.21.0, up to and including 5.21.4; from 6.0, up to and including 6.7

Published 2026-04-09. Last modified 2026-06-17.