CVE-2026-63300: An improper validation vulnerability in the instancePostMigration function in lxd/instance_post.go of LXD allows an authenticated attacker with…

PriorityP263critical9.9CVSS 3.1

AVNACLPRLUINSCCHIHAH

EPSS

0.29%

21.2th percentile

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

3 ranges

Vendor	Product	Version range	Fixed in
canonical	lxd	>= 5.0.0 < 5.0.8	5.0.8
canonical	lxd	>= 5.21.0 < 5.21.6	5.21.6
canonical	lxd	>= 6.0 < 6.10	6.10

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.