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.

Published: 2026-04-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-34177 is rated Moderate Risk (46.4/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.36%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-34177

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.16% 0.36% +0.21%
2 2026-05-11 0.10% 0.16% +0.05%
3 2026-04-09 — 0.10% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-34177

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.3 6.0 [email protected]

Weakness enumeration for CVE-2026-34177

GitHub Security Advisory for CVE-2026-34177

GHSA-fm2x-c5qw-4h6f · Severity: critical · Ecosystem: go — LXD: VM lowlevel restriction bypass via raw.apparmor and raw.qemu.conf

OS Trackers for CVE-2026-34177

vendor priority summary link
debian not yet assigned CVE-2026-34177 not yet assigned priority: Debian including 2 source packages (incus, lxd), 5 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-34177
ubuntu medium CVE-2026-34177 medium priority: Ubuntu including 2 source packages (incus, lxd), 13 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): DNE 5, not-affected 4, needs-triage 2, needed 1, released 1. https://ubuntu.com/security/CVE-2026-34177

Affected software / configurations for CVE-2026-34177

Vendor Product Version Raw CPE
canonical lxd >= 4.12, <= 5.0.6 cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*
canonical lxd >= 5.21.0, <= 5.21.4 cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*
canonical lxd >= 6.0, <= 6.7 cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*

References for CVE-2026-34177

cvelogic Threat Intelligence