Human error remains one of the most significant contributors to cybersecurity threats, leading to data breaches, system vulnerabilities, and financial loss. Thus, this paper examines causes and manifestations of human errors such as susceptibility to phishing attacks, analyzes prominent case studies in terms of their consequences and the operational, financial, and reputational risks associated with long recovery periods in addition to data loss. In response, we propose a structured framework for understanding and mitigating the impact of human error in cybersecurity systems. The framework is supported by mitigation strategies such as training, AI-assisted threat detection, and user-centered design, emphasizing the need for a holistic and layered approach to cybersecurity resilience.