The utilization of digital technologies in Nigeria’s security sector has enhanced Intelligence Surveillance and Reconnaissance (ISR), border security and control, communication, and law enforcement. Nonetheless, it has also heightened vulnerability to advanced cyber threats aimed at government systems and critical infrastructure. Malicious actors like criminals, hacktivists, terrorist organizations, and government-backed groups are taking advantage of these weaknesses in networks, databases, and communication systems to carry out their nefarious activities. This research examines new cyber threats and vulnerabilities in the sector through a qualitative method relying on literature, reports, and policy documents. Results indicate that significant dangers encompass ransomware, phishing, cyber espionage, political disinformation and misinformation, etc. Key vulnerabilities consist of outdated systems, lack of cybersecurity awareness, inadequate regulatory compliance, insufficient funding, and a deficit of skilled workers. Despite these obstacles, the research underscores opportunities including Artificial Intelligence (AI), Machine Learning, Zero Trust Models, Cyber threat intelligence systems, and enhanced governance. It determines that a unified national cybersecurity approach and heightened investment in technology and human resources are crucial for bolstering Nigeria’s cybersecurity resilience. The research is anchored on the Diffusion of Innovation Theory (DIT) for its analysis.