CVE-2026-66721 Apache CloudStack: Authorization issue with listHostTags for domain admins

Low 2.7 Published 21 Aug 2026 Updated 24 Aug 2026

Domain admins can view host tags for all hosts in the environment instead of only their own domain's hosts.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-66721?

CVE-2026-66721 is a low-severity missing authorization vulnerability in Apache Cloudstack, published on 21 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

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.

Weakness: CWE-862

Which versions are affected by CVE-2026-66721?

It affects 1 product.

Products include Apache Cloudstack.

How do I fix CVE-2026-66721?

No fix has been published for CVE-2026-66721 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-66721 being exploited?

There is no known exploitation of CVE-2026-66721 in the wild and no public exploit code.

All Apache Cloudstack vulnerabilities

Sources

Also known as GHSA-454g-wxrr-37fg.