BACKGROUND: With the ever-expanding interconnectedness of the internet and especially with the recent development of the Internet of Things, people are increasingly at risk for cybersecurity breaches that can have far-reaching consequences for their personal and professional lives, with psychological and mental health ramifications. OBJECTIVE: We aimed to identify the dimensional structure of emotion processes triggered by one of the most emblematic scenarios of cybersecurity breach, the hacking of one's smart security camera, and explore which personality characteristics systematically relate to these emotion dimensions. METHODS: A total of 902 participants from the United Kingdom and the Netherlands reported their emotion processes triggered by a cybersecurity breach scenario. Moreover, they reported on their Big Five personality traits, as well as on key indicators for resilient, overcontrolling (internalizing problems), and undercontrolling (aggression) personality types. RESULTS: Principal component analyses revealed a clear 3-dimensional structure of emotion processes: emotional intensity, proactive versus fight/flight reactions, and affective versus cognitive/motivational reactions. Regression analyses revealed that more internalizing problems (β=.33, P<.001), resilience (β=.22, P<.001), and agreeableness (β=.12, P<.001) and less emotional stability (β=-.25, P<.001) have significant predictive value for higher emotional intensity. More internalizing problems (β=.26, P<.001), aggression (β=.25, P<.001), and extraversion (β=.07, P=.01) and less resilience (β=-.19, P<.001), agreeableness (β=-.34, P<.001), consciousness (β=-.19, P<.001), and openness (β=-.22, P<.001) have significant predictive value for comparatively more fight/flight than proactive reactions. Less internalizing problems (β=-.32, P<.001) and more emotional stability (β=.14, P<.001) and aggression (β=.13, P<.001) have significant predictive value for a comparatively higher salience for cognitive/motivational than affective reactions. CONCLUSIONS: To adequately describe the emotion processes triggered by a cybersecurity breach, two more dimensions are needed over and above the general negative affectivity dimension. This multidimensional structure is further supported by the differential relationships of the emotion dimensions with personality characteristics. The discovered emotion structure could be used for consistent predictions about who is at risk to develop long-term mental well-being issues due to a cybersecurity breach experience.