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

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

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Aug 2026
- **Updated:** 21 Aug 2026
- **Also known as:** GHSA-6777-p72p-347g

## 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 (Improper Access Control)

## Which versions are affected by CVE-2026-66797?

It affects 1 product.


Products: 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.

## Is CVE-2026-66797 being exploited?

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

## Other vulnerabilities in Apache Cloudstack

- [CVE-2012-4501](https://insights.sbomify.com/CVE-2012-4501/): Missing authorization in n/a (critical 10.0)
- [CVE-2024-38346](https://insights.sbomify.com/CVE-2024-38346/): Apache CloudStack: Unauthenticated cluster service port leads to remote execution (critical 9.8)
- [CVE-2024-39864](https://insights.sbomify.com/CVE-2024-39864/): Apache CloudStack: Integration API service uses dynamic port when disabled (critical 9.8)
- [CVE-2024-29006](https://insights.sbomify.com/CVE-2024-29006/): Apache CloudStack: x-forwarded-for HTTP header parsed by default (critical 9.8)
- [CVE-2022-35741](https://insights.sbomify.com/CVE-2022-35741/): Apache CloudStack SAML Single Sign-On XXE (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-66797 and fix it if it is affected.

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

Affected product: Apache Cloudstack. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-66797/ (Markdown: https://insights.sbomify.com/CVE-2026-66797/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-66797
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-66797
- OSV: https://osv.dev/vulnerability/CVE-2026-66797

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-66797/
Summaries are generated and may contain mistakes; the official description above is the record.