A severity rubric is a scoring or grading guide used to decide how serious an incident is and how quickly it should be handled. It usually defines levels such as low, medium, high, and critical, with criteria for impact, scope, exploitability, and business risk. A good rubric removes guesswork so different analysts, teams, or organizations classify the same event in the same way.
In cyber security, severity rubrics are central to triage. They help defenders prioritize malware alerts, data leaks, service outages, vulnerable assets, and AI safety events. In attacks, an intruder may trigger many low-level signals at once; a rubric helps responders separate noise from events that need immediate containment. In defense, the rubric also supports escalation, patch timing, incident reporting, and communication with leadership. Without a shared rubric, teams can underreact to serious compromise or waste time on minor issues.