Vulnerability Report

CVE-2026-34178

Title: Canonical LXD Project Restriction Bypass via Backup Import

Input Validation Error

Proof Of Concept

No public PoC currently indexed for CVE-2026-34178.

CWE Category CWE-20

Published Date Apr 09, 2026

Modified Date Apr 22, 2026

Exploit Status Not Found

Score 9.1 CVSS v3.1

Exploit Probability (EPSS)

0.42%

Vulnerability Summary

CVE-2026-34178: In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml in the supplied tar archive but creates the instance from backup/container/backup.yaml, a separate file in the same archive that is never checked against project restrictions. An authenticated remote attacker with instance-creation permission in a restricted project can craft a backup archive where backup.yaml carries restricted settings such as security.privileged=true or raw.lxc directives, bypassing all project restriction enforcement and allowing full host compromise.

Impacted Vendors

canonical 1

linuxcontainers 1

Reference Links

https://github.com/canonical/lxd/pull/17921 https://github.com/canonical/lxd/security/advisories/GHSA-q96j-3fmm-7fv4

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