CVE-2026-66797 Apache CloudStack: Unauthorised comment creation and disclosure

Medium 5.4 Published 21 Aug 2026 Updated 21 Aug 2026

Authenticated users can create and view annotations on entities they do not own due to improper access control checks in Apache CloudStack.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-66797?

CVE-2026-66797 is a medium-severity missing authorization vulnerability in Apache Cloudstack, published on 21 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Improper access control in CloudStack's annotation functionality allows unauthorized comment creation and disclosure.

The addAnnotation and listAnnotation APIs perform an ownership check when an entity's UUID is specified, but fail to honor its result correctly. This lets any authenticated user write annotations to, and disclose existing annotations/comments on, an entity they don't own by simply supplying its UUID.

This issue affects Apache CloudStack: from 4.15.0.0 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-284

Which versions are affected by CVE-2026-66797?

It affects 1 product.

Products include Apache Cloudstack.

How do I fix CVE-2026-66797?

No fix has been published for CVE-2026-66797 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-2026-66797 being exploited?

There is no known exploitation of CVE-2026-66797 in the wild and no public exploit code.

All Apache Cloudstack vulnerabilities

Sources

Also known as GHSA-6777-p72p-347g.