CVE-2026-34177

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

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

Canonical · lxd

CVSS v3.1 UBUNTU

9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

EPSS

0.61% chance of exploitation in the next 30 days, 48th percentile

Published

2026-04-09

Proof-of-concept exploits (1)

• advisories/GHSA-fm2x-c5qw-4h6f

Security advisories

• canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f
• canonical/lxd/pull/17909

References

• CVE Record
• NVD entry