Missing Authorization in LXD - CVE-2026-63300
Published: August 1, 2026
Vulnerability identifier: #VU140683
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63300
CWE-ID: CWE-862
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code on the host.
The vulnerability exists due to missing authorization in instancePostMigration when moving an instance between projects on the same cluster member without validating the instance configuration against the target project's restrictions. A remote user can move a crafted instance from an unrestricted project to a restricted project to execute arbitrary code on the host.
The issue affects cross-project moves performed without the ?target= parameter, and exploitation can occur when the moved instance is later started.
Affected software
LXD
How to mitigate CVE-2026-63300
Install security update from vendor's website.
LXD - addressed in versions 5.0.8, 5.21.6, 6.10