Which terminology is used for a negative event impacting organizational security?

The terminology that best describes a negative event impacting organizational security is "Incident." An incident refers to any occurrence that actually has an adverse effect on the confidentiality, integrity, or availability of an organization’s information or information systems. This can include data breaches, malware infections, unauthorized access, or any other compromise of security.

The distinction here is that an incident typically implies that there has been a breach or a security event that has resulted in impacts that need to be addressed, often prompting a response or remediation effort from the organization.

In contrast, while the term "threat" refers to a potential cause of an unwanted incident, it does not define an actual occurrence. "Event" is a broad term that can refer to any observable occurrence in a system or network, not necessarily negative. "Risk" generally refers to the potential for loss or damage when a threat exploits a vulnerability, rather than being an event in itself. Thus, in the context of negative impacts on security, "Incident" is the most accurate terminology.