# CVE-2026-66797: Apache CloudStack improper access control in annotation APIs

Source: https://junglewise.ai/threats/cve-2026-66797-apache-cloudstack-improper-access-control-in-annotation-apis  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-21. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-66797 · Severity: medium · CVSS 5.4 · Published 2026-08-21

Apache CloudStack is a cloud management platform used to orchestrate infrastructure resources. A flaw in its annotation feature allows any authenticated user to create comments and read existing annotations on resources they don't own, potentially exposing sensitive information and enabling unauthorized modifications to shared infrastructure.

Technologies: [Apache Cloudstack](https://junglewise.ai/threats/technologies/cloudstack). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-66797 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-66797 being exploited in the wild.

**How severe is CVE-2026-66797?** Medium severity, with a CVSS score of 5.4, published 21 August 2026.

**Which products and versions are affected?** Apache Cloudstack 4.15.0.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0.

**Is there a fix for CVE-2026-66797?** 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-2026-66797 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-66797?** 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 vulnerability is an improper access control flaw in the addAnnotation and listAnnotation APIs. These APIs perform an ownership check when an entity UUID is supplied, but fail to correctly honor the result of that check. An authenticated attacker can bypass ownership restrictions by directly supplying a UUID of an entity they don't own, allowing them to both write new annotations/comments and read existing ones. The issue affects CloudStack versions 4.15.0.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0. Patches are available in versions 4.20.3.1 and 4.22.1.1 or later.

## Affected products

- Apache CloudStack 4.15.0.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0

## Timeline

- 2026-08-21: disclosed

## References

- [https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc](https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc)

## Related threats

- [Apache CloudStack resource leak in scoped global configuration](https://junglewise.ai/threats/cve-2026-59654-apache-cloudstack-resource-leak-in-scoped-global-configuration)
- [Apache CloudStack certificate validation bypass in SAML authentication](https://junglewise.ai/threats/cve-2026-68745-apache-cloudstack-certificate-validation-bypass-in-saml)
- [Apache CloudStack improper authorization in project role management](https://junglewise.ai/threats/cve-2026-66722-apache-cloudstack-improper-authorization-in-project-role)
- [Apache CloudStack authorization bypass in host tags listing](https://junglewise.ai/threats/cve-2026-66721-apache-cloudstack-authorization-bypass-in-host-tags-listing)
- [Apache CloudStack information disclosure in Webhook module](https://junglewise.ai/threats/cve-2026-65613-apache-cloudstack-information-disclosure-in-webhook-module)