CVE-2026-34177
LXD: VM lowlevel restriction bypass via raw.apparmor and raw.qemu.conf
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.
How to fix CVE-2026-34177
To remediate CVE-2026-34177, upgrade the affected package to a fixed version below.
- —upgrade to 6.0.2-1 or later
- —upgrade to 5.0.2-5+deb12u5 or later
- —no fix listed
Is CVE-2026-34177 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 6.0.2-1
- from 0, < 5.0.2-5+deb12u5
- >= 0.0.0-20210305023314-538ac3df036e, <= 0.0.0-20260226085519-736f34afb267
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.1 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |