Exception handling is the part of a security rule or control that defines when the default rule does not apply. In cyber security, exceptions are used for cases such as accessibility needs, emergency access, maintenance windows, or approved testing. A good exception process is specific, time-limited, logged, and reviewed, so the exception does not become a permanent loophole.
This matters because many attacks succeed by abusing weak exceptions. For example, an attacker may impersonate an approved user, exploit a “temporary” access grant that was never removed, or target systems where monitoring was disabled for an exemption. Defenders use exception handling to balance security with real-world needs, especially in access control, endpoint management, and policy enforcement. The goal is not to eliminate exceptions, but to make them visible, justified, and harder to abuse.