CVE-2026-66721: Apache Cloudstack

Low severity, CVSS 2.7. EPSS: 0.5% chance of exploitation in the next 30 days.

Missing authorization issue for domain admins in CloudStack's host tags listing functionality. Domain Admins, by default, have permission to call the listHostTags API, but the API returns host tags for every host in the environment without domain scoping. It should instead be restricted to only the hosts dedicated to that admin's domain. This issue affects Apache CloudStack: from 4.12.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0. Users are recommended to upgrade to version 4.20.3.1 or 4.22.1.1 or later, which fixes the issue.

Affected products

• Apache Cloudstack: from 4.12.0.0, before 4.20.3.1 (fixed in 4.20.3.1); from 4.21.0.0, before 4.22.1.1 (fixed in 4.22.1.1)

Published 2026-08-21. Last modified 2026-08-27.