by Kastro
Paper/Archive/CVE-2026-34177

CVE-2026-34177

Canonical lxd — VM lowlevel restriction bypass via raw.apparmor and raw.qemu.conf

EPSS 0.4%public exploitCVSS 9.1
critical.is priorityof 100
43
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 30.1.301 × 206.0Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
lxd4.12.0 – < 5.0.75.0.7CNA
lxd5.1.0 – < 5.21.55.21.5CNA
lxd6.0.0 – < 6.8.06.8.0CNA

Scores by source

canonical (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6fpatchgithub.com/canonical/lxd/pull/17909