Zero Trust is an essential aspect of security architecture, but many implementations fail to meet their objectives and deliver demonstrable security benefits. This report bridges the gap between Zero Trust deployments and security validation by providing a practical and comprehensive testing framework mapped to MITRE ATT&CK across key Zero Trust pillars: people, devices, workloads, networks, and data. Security leaders can use this report to learn practical methods for systematically validating controls, identifying vulnerabilities, and continuously improving security posture through adversarial testing of their Zero Trust implementation.