CVE-2026-72526 in Advanced Cluster Management for Kubernetes
Summary
by MITRE • 08/12/2026
A flaw was found in the multicloud-integrations component. The Application propagation controller processes the `ocm-managed-cluster` annotation from an Application Custom Resource (CR) without proper validation. A tenant with permissions to create Applications on the hub cluster can exploit this to target arbitrary managed clusters. This can force ArgoCD on the spoke clusters to synchronize attacker-controlled manifests, leading to arbitrary code execution or privilege escalation on those clusters.
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Analysis
by VulDB Data Team • 08/12/2026
This vulnerability exists within the multicloud-integrations component of a Kubernetes-based multi-cluster management system where the Application propagation controller fails to properly validate the ocm-managed-cluster annotation field in Application Custom Resources. The flaw represents a critical authorization bypass that allows tenants with minimal permissions to manipulate cluster targeting through crafted annotations, effectively enabling privilege escalation and arbitrary code execution across managed clusters.
The technical implementation of this vulnerability stems from insufficient input validation within the Application propagation controller logic. When processing Application CRs, the system accepts the ocm-managed-cluster annotation without proper sanitization or authorization checks, allowing malicious actors to specify arbitrary target clusters in the annotation field. This design flaw aligns with CWE-20: Improper Input Validation and represents a classic case of insecure direct object reference where the controller directly trusts user-provided cluster identifiers without verification against legitimate cluster inventories.
Operationally, this vulnerability enables attackers to achieve significant impact through a multi-stage attack vector that begins with creating an Application CR containing malicious annotations. The exploitation process allows tenants to force ArgoCD instances on spoke clusters to synchronize attacker-controlled manifests, effectively bypassing the normal cluster authorization mechanisms. This creates opportunities for privilege escalation, code execution, and potential lateral movement within the multi-cluster environment, particularly when managed clusters contain sensitive workloads or administrative privileges.
The attack scenario demonstrates a sophisticated exploitation pattern that leverages the trust model inherent in multi-cluster management systems. By crafting Application CRs with malicious ocm-managed-cluster annotations, attackers can effectively hijack the synchronization process of ArgoCD on target clusters, potentially leading to complete compromise of those environments. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1078 Valid Accounts and T1566 Phishing, where compromised or improperly authorized accounts can be leveraged for privilege escalation.
Mitigation strategies should focus on implementing strict validation of all annotations within Application CRs, particularly those referencing managed clusters. The system must enforce cluster authorization checks against legitimate inventory before processing any synchronization requests. Organizations should implement principle of least privilege controls, ensuring that only authorized users can create or modify Application CRs with cluster targeting capabilities. Additionally, network segmentation and monitoring should be implemented to detect anomalous synchronization patterns across managed clusters, while regular audits of cluster annotations and access controls should be performed to prevent unauthorized exploitation.