KEV, EPSS and SSVC turn exploitation evidence and likelihood into different prioritisation signals

Three different tools answer three different questions about the same flaw.

A known-exploited catalogue tells you it is definitely being used. A likelihood score estimates the chance it will be. A decision framework asks what you should do given your circumstances. They are complementary rather than competing, and organisations often adopt one and treat it as the whole answer, which is how a low-likelihood flaw on a critical system gets ignored.