CVE-2026-34177

EUVD-2026-20872
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.1 CRITICAL
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 29.64%
Affected Products (NVD)
VendorProductVersion
canonicallxd
4.12 ≤
𝑥
≤ 5.0.6
canonicallxd
5.21.0 ≤
𝑥
≤ 5.21.4
canonicallxd
6.0 ≤
𝑥
≤ 6.7
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
incus
forky
7.0.1-2
fixed
sid
7.0.1-2
fixed
trixie
6.0.4-2+deb13u8
fixed
trixie (security)
6.0.4-2+deb13u9
fixed
lxd
bookworm
vulnerable
bookworm (security)
vulnerable
trixie
5.0.2+git20231211.1364ae4-9+deb13u7
fixed
trixie (security)
5.0.2+git20231211.1364ae4-9+deb13u7
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
incus
jammy
dne
noble
needed
questing
not-affected
resolute
not-affected
lxd
bionic
not-affected
focal
not-affected
jammy
dne
noble
dne
questing
dne
resolute
dne
xenial
not-affected