Extended reality (XR) -- encompassing virtual reality (VR), augmented reality (AR), and mixed reality (MR) -- emerges as a potential transformative tool in educational realms. This article explores the potential of XR in facilitating mathematics assessments; it proposes a list of mathematical topics that could be effectively mediated by XR's immersive and interactive features. Additionally, it discusses some major challenges which could be barriers to the widespread adoption of XR in educational contexts and sets out a research agenda for further investigation.