In a variety of industries, including agriculture, engineering, environment, transportation, and the military, wireless sensor networks (WSNs) have revolutionized human life. Although WSNs are often utilised for tracking, monitoring, and controlling applications, their resource-constrained nature presents new difficulties. Utilizing a secure network is a fundamental need for all applications. The sensor network's security and energy efficiency are two very complex challenges. The operation of these networks may be impacted by several security threats. Given that WSNs are designed for remote surveillance and that unauthorized changes to sensed data may result in incorrect information being provided to decision makers, it is important to protect them from attack. This includes preventing attackers from obstructing sensor information delivery and from forging sensor information. This paper provides a concise overview of key security concerns and threats in WSN