Vulnerability Report

CVE-2026-34177

Title: Canonical LXD Privilege Escalation via Incomplete Denylist

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2026-34177.

CWE Category CWE-184

Published Date Apr 09, 2026

Modified Date Apr 22, 2026

Exploit Status Not Found

Score 9.1 CVSS v3.1

Exploit Probability (EPSS)

0.36%

Vulnerability Summary

CVE-2026-34177: 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.

Impacted Vendors

canonical 1

linuxcontainers 1

Reference Links

https://github.com/canonical/lxd/pull/17909 https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f

CVSS v3.1

Source Entity [email protected]

Severity CRITICAL

9.1

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns