Quick answers
- Is CVE-2026-66721 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-66721 being exploited in the wild.
- How severe is CVE-2026-66721?
- Low severity, with a CVSS score of 2.7, published 21 August 2026.
- Which products and versions are affected?
- Apache Cloudstack 4.12.0.0 through 4.20.3.0, 4.21.0.0 through 4.22.1.0.
- Is there a fix for CVE-2026-66721?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-66721 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-66721?
- Check whether you run Apache Cloudstack at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The listHostTags API in Apache CloudStack fails to enforce domain-level authorization checks when called by Domain Admins. Although Domain Admins are permitted to call the API by default, the implementation returns all host tags in the system without filtering by the caller's domain scope. This is a broken access control vulnerability allowing Domain Admins to enumerate infrastructure outside their administrative domain. The issue affects versions 4.12.0.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0, and is fixed in 4.20.3.1 and 4.22.1.1 or later. Authentication as a Domain Admin is required to exploit this issue.
Affected products
- Apache CloudStack 4.12.0.0 through 4.20.3.0, 4.21.0.0 through 4.22.1.0
Timeline
- 2026-08-21: disclosed