Fifth Generation (5G) networks represent a transformative leap in the world of telecommunications, as they aim not only to increase data transfer speeds but also to establish a flexible infrastructure capable of accommodating the vast diversity of modern application and service requirements. At the heart of realizing this vision, network slicing technology emerges as one of the most significant architectural innovations that redefine how networks operate. However, this technology raises security concerns, which pose challenges that necessitate in-depth research and analysis. Therefore, it is essential to develop new security solutions that align with the dynamic nature of 5G networks, taking into account several security issues such as isolation between slices, authentication, and authorization. This study presents a systematic review of recent scientific research focusing on securing network slices in 5G environments. The review is based on peer-reviewed articles collected from trusted academic databases and offers practical and applicable recommendations to enhance 5G network security. The paper emphasizes the protection of network slicing technology from potential threats across three critical levels: Life-cycle Security, Intra-slice Security, and Inter-slice Security. The literature review highlights the extensive research interest in 5G network slicing, with particular attention to intelligent resource management using Deep Learning techniques such as the DeepSlice model to enhance network speed and flexibility. It also discusses the application of Lyapunov Stability Theory, a robust mathematical method to ensure system stability under data scarcity, and Multi-Agent Reinforcement Learning (MARL) for End-to-End resource management. Enabling technologies such as Network Function Virtualization (NFV) and Software Defined Networking (SDN) are identified as foundational pillars of network slicing. AI-based security solutions have been developed to accurately detect Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks. Some studies simulate attacks to analyze vulnerabilities and strengthen defenses using techniques like Federated Learning and Onion Routing combined with end-to-end encryption to ensure data confidentiality and anonymity within slices. This paper is the first prepared in Arabic in this field, providing a scientific review of the security aspects of network slicing. It selects scientific papers published over the past five years that focus on the security aspect of network slicing technology, contributing to enriching the Arabic scientific content in this specialization............... Keywords:........... Network Slicing, 5G Networks, Slice Isolation, Authentication, Authorization, Security Threats, Virtual Networks, Life-cycle Security, Intra-slice Security, Inter-slice Security.