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

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

Which versions are affected by CVE-2025-66171?

It affects 1 product.

Products include 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.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

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 Missing authorization in n/a Critical 10.0
• CVE-2024-38346 Apache CloudStack: Unauthenticated cluster service port leads to remote execution Critical 9.8
• CVE-2024-39864 Apache CloudStack: Integration API service uses dynamic port when disabled Critical 9.8
• CVE-2024-29006 Apache CloudStack: x-forwarded-for HTTP header parsed by default Critical 9.8
• CVE-2022-35741 Apache CloudStack SAML Single Sign-On XXE Critical 9.8

All Apache Cloudstack vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5f56-5m8x-gjf9.