The rapid adoption of multi-cloud strategies by organizations, particularly those in highly regulated sectors such as finance, healthcare, and government, has introduced a new and complex set of security challenges. While offering significant benefits in flexibility and scalability, multi-cloud environments lack a unified security framework, leading to fragmented security controls, inconsistent configuration baselines, and a proliferation of vulnerabilities. Traditional, single-cloud security models and manual vulnerability management processes are proving to be inadequate in this dynamic, interconnected landscape. This paper proposes a comprehensive, multi-layered protocol designed to establish and enforce secure configuration baselines and to provide continuous, automated vulnerability management across diverse cloud platforms. Drawing on a synthesis of industry best practices, established regulatory mandates (e.g., GDPR, HIPAA), and technological advancements in cloud security posture management (CSPM) and security information and event management (SIEM), the proposed protocol provides a structured approach for risk identification, assessment, and remediation. The framework focuses on five core pillars: automated discovery and asset inventory; centralized policy enforcement and baseline configuration; continuous monitoring and real-time alerting; automated remediation workflows; and a unified, cross-platform reporting mechanism. By addressing the inherent complexities of multi-cloud governance, this paper aims to provide a robust and scalable model for organizations to proactively manage their security posture and maintain regulatory compliance.