The rapid adoption of multi-cloud environments where organizations use services from multiple cloud providers simultaneously has transformed modern IT infrastructure. Multi-cloud strategies offer flexibility, cost optimization, and reduced vendor lock-in, but they also introduce significant security challenges. These challenges arise due to varied architectures, inconsistent security controls, increased attack surfaces, and complex data governance requirements. This paper examines the key security risks associated with multi-cloud ecosystems, reviews existing literature, outlines research objectives, and presents a systematic methodology. Furthermore, it highlights major findings and provides practical recommendations to strengthen multi-cloud security. The study concludes that while multi-cloud adoption is beneficial, organizations must implement comprehensive security frameworks to mitigate associated risks.