# CVE-2025-66171

## Summary

- **CVE ID:** CVE-2025-66171
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** CWE-359
- **Published:** May 8, 2026
- **Last Modified:** May 9, 2026

## 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.

## Affected Products

- Apache Software Foundation — Apache CloudStack (4.21.0.0)

## References

- [CNA](https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm)
- [CVE](http://www.openwall.com/lists/oss-security/2026/05/09/2)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.53%
- **EPSS Percentile:** 43.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._