{"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":0.00357,"epssPercentile":0.2937,"ingestedAt":"2026-09-11T17:50:33.511Z","slug":"CVE-2026-63300","body":"## Overview\n\nAn 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.\n\n## Affected\n\n- `lxd >= 5.0.0, < 5.0.8`\n- `lxd >= 5.1, < 5.21.6`\n- `lxd >= 6.0, < 6.10`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `lxd 6.10`","depth":"midnight","depthScore":55,"depthScoreParts":{"impact":54.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}