# CVE-2025-66171: Apache CloudStack: Any user can create a new VM from backups they should not have access to

> Authenticated users can create VMs from other users' backups due to improper access logic in the CloudStack Backup plugin.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:** 8 May 2026
- **Updated:** 9 May 2026
- **Also known as:** GHSA-5f56-5m8x-gjf9

## What is CVE-2025-66171?

CVE-2025-66171 is a medium-severity missing authorization vulnerability in Apache Cloudstack, published on 8 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The CloudStack Backup plugin has an improper access logic in versions 4.21.0.0 and 4.22.0.0. Anyone with authenticated user-account access in CloudStack 4.21.0.0+ environments, where this plugin is enabled and have access to specific APIs can create new VMs using backups of any other user of the environment.

Backup plugin users using CloudStack 4.21.0.0+ are recommended to upgrade to CloudStack version 4.22.0.1, which fixes this issue.

Weakness: CWE-359 (Exposure of Private Personal Information to an Unauthorized Actor)

## Which versions are affected by CVE-2025-66171?

It affects 1 product.


Products: Apache Cloudstack.

## How do I fix CVE-2025-66171?

No fix has been published for CVE-2025-66171 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66171 being exploited?

There is no known exploitation of CVE-2025-66171 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-2025-66171 and fix it if it is affected.

What it is: CVE-2025-66171 is a medium-severity missing authorization vulnerability in Apache Cloudstack, published on 8 May 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-2025-66171 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-2025-66171/ (Markdown: https://insights.sbomify.com/CVE-2025-66171/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66171
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66171
- OSV: https://osv.dev/vulnerability/CVE-2025-66171

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66171/
Summaries are generated and may contain mistakes; the official description above is the record.