What is the CVSS score of CVE-2026-34177?

CVE-2026-34177 has a CVSS 3.1 base score of 9.1 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

How to fix or mitigate CVE-2026-34177?

Within 24 hours: Identify all LXD deployments running versions 4.12-6.7 and restrict VM instance editing permissions to trusted administrators only. Within 7 days: Apply vendor-released patch to upgrade LXD to version 6.8 or later across all affected clusters. Within 30 days: Conduct access audit to verify no unauthorized privilege escalations occurred, review AppArmor and QEMU configuration logs for injection attempts, and update VM editing RBAC policies to enforce principle of least privilege.

Lxd CVE-2026-34177

Q: Which versions of Lxd are affected by CVE-2026-34177?

CVE-2026-34177 is a critical privilege escalation vulnerability in Canonical LXD versions 4.12-6.7 that allows authenticated users with VM editing permissions to escape project isolation and gain…. A patch is available.

EUVD-2026-20872 CRITICAL

Incomplete List of Disallowed Inputs (CWE-184)

2026-04-09 canonical

GHSA-fm2x-c5qw-4h6f

Privilege Escalation Canonical Lxd

9.1

CVSS 3.1 · Vendor: canonical

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate as VM editor in restricted project
Delivery

Inject raw.apparmor and raw.qemu.conf rules
Exploit

Bridge LXD Unix socket into guest VM
Execution

Escape VM and escalate to LXD administrator
Impact

Gain host root access

Vulnerability Assessment

Weakness	CWE CWE-184 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V2 - Validation and Business Logic Input validation completeness
Exploitation Conditions	Canonical LXD 4.12–6.7 with restricted.virtual-machines.lowlevel=block project restriction enabled. Attacker requires can_edit permission on a VM instance. No user interaction needed. Exploitation bypasses incomplete denylist to inject raw.apparmor and raw.qemu.conf, escalating to LXD admin and host root.
Impact	CVSS 9.1 reflects critical severity with network accessibility and high impact across confidentiality, integrity, and availability. However, authentication requirement (PR:H) and patch availability significantly reduce real-world blast radius. Risk concentrates on multi-tenant LXD deployments where untrusted users hold can_edit VM permissions. Organizations on affected versions (4.12-6.7) face privilege escalation to host root via denylist bypass.
Exploit ScenarioDerived	Authenticated attacker with can_edit VM permissions injects raw.apparmor and raw.qemu.conf directives to bridge LXD Unix socket into guest, escalating to cluster administrator then host root. No public exploit identified at time of analysis.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.

Patch available 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Apr 09, 2026

Privilege escalation in Canonical LXD 4.12-6.7 allows authenticated remote attackers with VM instance editing rights to bypass project restrictions via incomplete denylist validation. Attackers inject AppArmor rules and QEMU chardev configurations through unblocked raw.apparmor and raw.qemu.conf keys, bridging the LXD Unix socket into guest VMs. Successful exploitation enables escalation to LXD cluster administrator and subsequently to host root access. No public exploit identified at time of analysis. Authenticated remote exploitation (PR:H) with cross-scope impact on confidentiality, integrity, and availability.

RemediationAI

Vendor-released patch: Upgrade to Canonical LXD version 6.8 or later, which implements complete denylist validation blocking raw.apparmor and raw.qemu.conf keys in restricted projects. Apply upstream fix available via GitHub pull request https://github.com/canonical/lxd/pull/17909. Review project restriction configurations and audit can_edit permission grants on VM instances in restricted projects. As interim mitigation, revoke can_edit permissions from non-administrative users in projects enforcing restricted.virtual-machines.lowlevel=block until patching completes. Consult vendor security advisory https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f for deployment-specific guidance and validation procedures.

Affected VersionsENISA

LXD 6.0.0 <6.8.0

LXD 5.1.0 <5.21.5

LXD 4.12.0 <5.0.7

Affected Packages

go github.com/canonical/lxd no fix

euvd lxd fix: 5.0.7, 5.21.5, 6.8.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 2 packages in go, euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

CWE-184 incomplete denylist vulnerability in isVMLowLevelOptionForbidden function (lxd/project/limits/permissions.go) fails to block raw.apparmor and raw.qemu.conf keys under restricted.virtual-machines.lowlevel=block project restriction. Attackers leverage omitted validation to inject QEMU chardev configurations exposing the LXD management socket to guest VM environments, enabling unauthorized privileged operations.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (canonical) PRIMARY 9.1 CRITICAL

AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

SUSE CRITICAL

Primary rating from Vendor (canonical).

CVSS VectorVendor: canonical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch released

Apr 09, 2026 - 09:30 nvd

Patch available

CVE Published

Apr 09, 2026 - 09:15 nvd

CRITICAL 9.1

DescriptionCVE.org

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.

Executive ViewAI

Why It Matters

CVE-2026-34177 is a critical privilege escalation vulnerability in Canonical LXD versions 4.12-6.7 that allows authenticated users with VM editing permissions to escape project isolation and gain cluster administrator access, ultimately compromising host root security. Organizations running multi-tenant LXD clusters face immediate risk of data breach, service disruption, and unauthorized system access from internal or compromised VM operators.

Business Impact: Severe

Compensating Controls

Apply vendor patch. Until patching: (1) Revoke raw.apparmor and raw.qemu.conf editing capabilities from non-administrative users via LXD profile restrictions; (2) Implement network-level access controls limiting LXD Unix socket exposure; (3) Enable comprehensive audit logging of all configuration changes; (4) Enforce approval workflows for any VM instance modifications in multi-tenant environments.

Threat Intelligence Overview

EPSS Score

0.1%

Top 72% exploitable

Threat Intel

1 source

Social Media

Sightings

Data Quality

7 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment GHSA Vendor CIRCL

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC No

EPSS 0.1%

Patch available Yes

Active threat No

Deciding rule

CRITICAL severity

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision

Out-of-Cycle

Exploitation

Poc

System Exposure· derived

Open

Automatable

Human Impact

Very High

Technical Impact

Total

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +46

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.