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LxdApplication · Canonical

CVE-2026-34177

CRITICAL · 9.1 CVSS v3.1 Published 2026-04-09
Fix available
A fix is available. Upgrade to after 6.7 or later.
See remediation →
97/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LxdApplication
Affected:>= 4.12, <= 5.0.6>= 5.21.0, <= 5.21.4>= 6.0, <= 6.7

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 6.7
Vendor patch github.com →
Recommended fix Moderate confidence

Upgrade to LXD version > 6.7 (the next stable release containing the fix in PR #17909)

  1. 1. Identify all LXD installations in the environment and note their version numbers
  2. 2. For each affected version (<=5.0.6, <=5.21.4, or <=6.7), plan an upgrade to a patched release
  3. 3. Before upgrading in production, test the upgrade in a non-production environment
  4. 4. Back up LXD data and configurations
  5. 5. Apply the vendor upgrade using the distribution's package manager (e.g., apt upgrade lxd or snap refresh lxd)
  6. 6. Verify the upgrade was successful by checking `lxd version`
  7. 7. Confirm the restricted.virtual-machines.lowlevel=block setting now properly blocks raw.apparmor and raw.qemu.conf
Caveat Review LXD release notes for the target version for any breaking changes between current and new versions

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $2,300. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-34177 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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