---
id: CVE-2026-63300
title: >-
  An improper validation vulnerability in the instancePostMigration function in
  lxd/instance_post.go of LXD allows an authenticated attacker with
  can_create_instances permissions on a restricted project to bypass
  project-level security res…
summary: >-
  An improper validation vulnerability in the instancePostMigration function in
  lxd/instance_post.go of LXD allows an authenticated attacker with
  can_create_instances permissions on a restricted project to bypass
  project-level security res…
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-862
vendor: canonical
product: lxd
affected:
  - 'lxd >= 5.0.0, < 5.0.8'
  - 'lxd >= 5.1, < 5.21.6'
  - 'lxd >= 6.0, < 6.10'
patched:
  - lxd 6.10
published: '2026-08-12'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T15:21:14.557'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63300'
references:
  - url: 'https://github.com/canonical/lxd/pull/18605'
    label: security@ubuntu.com
  - url: 'https://github.com/canonical/lxd/pull/18651'
    label: security@ubuntu.com
  - url: 'https://github.com/canonical/lxd/security/advisories/GHSA-5g5r-wh97-qcq2'
    label: security@ubuntu.com
tags:
  - nvd
epss: 0.00539
epssPercentile: 0.42978
ingestedAt: '2026-09-11T17:50:33.511Z'
---

## Overview

An improper validation vulnerability in the instancePostMigration function in lxd/instance_post.go of LXD allows an authenticated attacker with can_create_instances permissions on a restricted project to bypass project-level security restrictions. When migrating an instance between projects, LXD fails to validate the instance's configuration against the target project's enforced restrictions (such as restricted.containers.lowlevel, restricted.devices.*, and restricted.networks.access). An attacker can exploit this by creating a disallowed or high-privilege instance in an unrestricted project and subsequently moving it into the restricted project.

## Affected

- `lxd >= 5.0.0, < 5.0.8`
- `lxd >= 5.1, < 5.21.6`
- `lxd >= 6.0, < 6.10`

## Remediation

Upgrade past the affected range:

- `lxd 6.10`