CVE-2026-59654 in CloudStack
Summary
by MITRE • 08/21/2026
Missing Release of Resource after Effective Lifetime vulnerability in Apache CloudStack's scoped global configuration functionality. It affects different modules and plugins of the CloudStack management server, including Quota, Host-HA, etc., and may lead to eventual denial of service (DoS) scenario for the management server.
This issue affects Apache CloudStack: from 4.7.0 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.
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Analysis
by VulDB Data Team • 08/21/2026
The vulnerability identified in Apache CloudStack represents a critical resource management flaw within its scoped global configuration functionality. This defect is categorized under CWE-770 as Allocation of Resources Without Limits or Throttling, specifically manifesting as a missing release of resources after their effective lifetime has expired. The issue permeates multiple core modules and plugins that constitute the Apache CloudStack management server architecture, including but not limited to the Quota module and Host-High Availability (Host-HA) mechanisms. These components are responsible for managing infrastructure limits and ensuring system resilience in cloud environments, making their stability paramount for operational continuity.
The technical root cause lies in the lifecycle management of configuration objects within these modules. When scoped global configurations are instantiated or modified, they consume specific memory resources on the management server. Under normal operation, once a configuration scope expires or is invalidated, the associated resource handles should be explicitly released back to the system pool. However, due to this vulnerability, the cleanup logic fails to execute properly in certain scenarios. Consequently, references to these objects are not dereferenced and garbage collection cannot reclaim the memory they occupy. This leads to a gradual accumulation of unreleased resources over time as configuration changes occur within the cloud environment.
The operational impact of this flaw is severe, primarily resulting in an eventual denial of service for the Apache CloudStack management server. As the leak persists during routine administrative operations or automated scaling events, the memory footprint of the Java Virtual Machine hosting the management server expands continuously. Eventually, the system exhausts its available heap space, leading to out-of-memory errors that crash the management process. Since the management server is the central control plane for the entire cloud infrastructure, its failure renders all virtual machine operations, network configurations, and storage provisioning unavailable. This effectively halts all cloud services until the service is manually restarted or the underlying resource leak is resolved.
This vulnerability affects a broad range of Apache CloudStack versions, specifically impacting releases from 4.7.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0. Organizations running any version within these ranges are at risk if they perform frequent configuration changes or utilize the affected modules extensively. The lack of immediate exploitation complexity means that even standard administrative tasks can trigger the leak, making it a persistent threat to long-term system stability rather than an exploit requiring specific malicious input from external actors.
To mitigate this vulnerability and restore operational integrity, administrators must upgrade their Apache CloudStack deployment immediately. The recommended action is to migrate to version 4.20.3.1 or 4.22.1.1 or any later release where the resource cleanup logic has been corrected. Prior to upgrading, it is advisable to monitor memory usage trends on the management server hosts to assess the severity of existing leaks and plan for a maintenance window that allows for service restoration after the upgrade. Additionally, implementing robust monitoring alerts for heap memory consumption can help detect similar issues in other components early, ensuring proactive defense against resource exhaustion attacks or defects.