The recent advancements in Virtual Reality (VR) and Augmented Reality (AR) research have significantly shifted towards enhancing privacy and security measures within these immersive environments. A notable trend is the exploration of novel vulnerabilities and their potential exploitation, particularly through the use of advanced sensing technologies like millimeter-wave (mmWave) radar. These studies underscore the critical need for robust privacy protection mechanisms to safeguard user data from unauthorized access and misuse. Additionally, there is a growing emphasis on integrating biometric authentication and encryption techniques to ensure secure and personalized user experiences in XR environments. The field is also witnessing innovative approaches to privacy protection in AR content sharing, where hierarchical encryption methods are being developed to dynamically adjust security levels based on the context. Furthermore, the application of VR technology in healthcare, specifically for rehabilitation and action evaluation, is emerging as a promising area, leveraging deep learning models to provide cost-effective and accessible monitoring solutions. Overall, the current research landscape is characterized by a concerted effort to balance the immersive capabilities of XR technologies with stringent privacy and security protocols, ensuring that user data remains protected against emerging threats.