---
id: CVE-2026-63297
title: >-
  An authorization bypass vulnerability in LXD due to a timing flaw during
  configuration merging allows an authenticated attacker to bypass target
  project restrictions during cross-project instance copies
summary: >-
  An authorization bypass vulnerability in LXD due to a timing flaw during
  configuration merging allows an authenticated attacker to bypass target
  project restrictions during cross-project instance copies. When copying an
  instance to a tar…
severity: critical
cvss: 9.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-367
  - CWE-863
vendor: canonical
product: lxd
affected:
  - 'lxd >= 5.0.0, < 5.0.8'
  - 'lxd >= 5.1, < 5.21.6'
  - 'lxd >= 6.0, < 6.9'
patched:
  - lxd 6.9
published: '2026-08-12'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T15:18:18.907'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63297'
references:
  - url: 'https://github.com/canonical/lxd/security/advisories/GHSA-v989-qw7w-xvg4'
    label: security@ubuntu.com
  - url: 'https://github.com/canonical/lxd/security/advisories/GHSA-v989-qw7w-xvg4'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-13T14:28:52.383092Z'
ingestedAt: '2026-09-13T11:28:38.759Z'
epss: 0.00343
epssPercentile: 0.25157
---

## Overview

An authorization bypass vulnerability in LXD due to a timing flaw during configuration merging allows an authenticated attacker to bypass target project restrictions during cross-project instance copies. When copying an instance to a target project, LXD performs restriction checks before configuration merging is complete, creating a time-of-check to time-of-use (TOCTOU) condition. An attacker can exploit this flaw to copy instances with disallowed high-privilege configurations into restricted projects, bypassing security controls.

## Affected

- `lxd >= 5.0.0, < 5.0.8`
- `lxd >= 5.1, < 5.21.6`
- `lxd >= 6.0, < 6.9`

## Remediation

Upgrade past the affected range:

- `lxd 6.9`