The Attack Severity Summary monitor of the Dashboard page displays statistics for the unacknowledged alerts in the logged-in domain. Alerts are categorized by system impact severity level: High, Medium, Low and Informational.
Each time the Manager starts on the Manager server, the last 100,000 High, Medium, Low, and Informational alerts are retrieved from the database. After the Manager starts, any unacknowledged alerts are added to that initial 100,000. The alert count is calculated across all admin domains, so the total count of 100,000 alerts is based on time and not on admin domain. For example, out of 100,000 unacknowledged alerts, admin domain A may have 80,000, while admin domain B may have 20,000. If you login with a Super User role, you will see alerts across all admin domains, where as users logged in with other user roles will see alerts specific to their domain.