The Apache CloudStack project has just announced the LTS release of Apache CloudStack 4.20.3.0 and 4.22.0.1 to address multiple security vulnerabilities affecting several CloudStack components and integrations.

These vulnerabilities include unauthorized access to backup resources, cross-tenant access issues, improper enforcement of resource limits, and security policy handling weaknesses in external integrations. Several of the reported issues may allow authenticated users to access or manipulate resources outside their intended scope.

The following CVEs are addressed in these releases:

• CVE-2025-66170 (severity ‘Low’)
• CVE-2025-66171 (severity ‘Important’)
• CVE-2025-66172 (severity ‘Important’)
• CVE-2025-66467 (severity ‘Important’)
• CVE-2025-69233 (severity ‘Moderate’)
• CVE-2026-25077 (severity ‘Important’)
• CVE-2026-25199 (severity ‘Moderate’)

 

 

CVE-2025-66170: Any user can list backups that they should not have access to

The CloudStack Backup plugin has an improper authorization 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 list backups from any account in the environment. This vulnerability does not allow them to see the contents of the backup.

Affected versions:

Apache CloudStack 4.21.0.0 through 4.22.0.0.

 

Resolution

Users are recommended to upgrade to version 4.22.0.1 or later, which addresses these issues.

 

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

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.

Affected versions:

Apache CloudStack 4.21.0.0 through 4.22.0.0

 

Resolution

Users are recommended to upgrade to version 4.22.0.1 or later, which addresses these issues.

 

 

CVE-2025-66172: Any user can attach a volume in their VMs from backups they should not have access to

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 restore a volume from any other user’s backups and attach the volume to their own VMs.

 

Affected versions:

Apache CloudStack 4.21.0.0 through 4.22.0.0

 

Resolution

Users are recommended to upgrade to version 4.22.0.1 or later, which addresses these issues.

 

 

CVE-2025-66467: MinIO policy remains intact on bucket deletion

Missing MinIO policy cleanup on bucket deletion via Apache CloudStack allows users to retain access to buckets which they previously owned. If another user creates a new bucket with the same name, the previous owners can gain unauthorized read and write access to it by using the previously generated access and secret keys.

 

Affected versions:

• Apache CloudStack 4.19.0.0 through 4.20.2.0
• Apache CloudStack 4.21.0.0 through 4.22.0.0

 

Resolution

Users are recommended to upgrade to version 4.20.3.0 or 4.22.0.1 or later, which addresses these issues.

 

 

CVE-2025-69233: Domain/account resource limits not honoured

Due to multiple time-of-check time-of-use race conditions in the resource count check and increment logic, as well as missing validations, users of the platform are able to exceed the allocation limits configured for their accounts/domains. This can be used by an attacker to degrade the infrastructure’s resources and lead to denial of service conditions.

 

Affected versions:

• Apache CloudStack 4.0.0 through 4.20.2.0
• Apache CloudStack 4.21.0.0 through 4.22.0.0

 

Resolution

Users are recommended to upgrade to version 4.20.3.0 or 4.22.0.1 or later, which addresses these issues.

 

 

CVE-2026-25077: Unauthenticated Command Injection in Direct Download Templates

Account users are allowed by default to register templates to be downloaded directly to the primary storage for deploying instances using the KVM hypervisor. Due to missing file name sanitization, an attacker can register malicious templates to execute arbitrary code on the KVM hosts. This can result in the compromise of resource integrity and confidentiality, data loss, denial of service, and availability of the KVM-based infrastructure managed by CloudStack.

Affected versions:

• Apache CloudStack 4.11.0 through 4.20.2.0
• Apache CloudStack 4.21.0.0 through 4.22.0.0

 

Resolution

Users are recommended to upgrade to version 4.20.3.0 or 4.22.0.1 or later, which addresses the issue.

 

 

CVE-2026-25199: Proxmox Extension Allows Unauthorised Cross-Tenant Instance Access

The Proxmox extension for CloudStack improperly uses a user-editable instance setting, proxmox_vmid, to associate CloudStack instances with Proxmox virtual machines. Because this value is not restricted or validated against tenant ownership and Proxmox VM IDs are predictable, a non-privileged attacker can modify the setting to reference a VM belonging to another account. This allows unauthorized cross-tenant access and enables full control over the targeted VM, including starting, stopping, and destroying the virtual machine.

 

Affected versions:

Apache CloudStack 4.21.0.0 through 4.22.0.0

 

Resolution

Users are recommended to upgrade to version 4.22.0.1 or later, which addresses these issues.

 

Official release notes can be found here: https://docs.cloudstack.apache.org/en/4.22.0.1/releasenotes/index.html