What's the probability shift?

FIRST’s EPSS machine-learning model estimates the probability that a CVE will be exploited in the wild in the next 30 days. Scores change as the model’s inputs evolve, including newly available exploit code and other vulnerability signals.

EPSS Watch compares these published probabilities over time so you can spot increases and decide what needs investigation. A rise does not tell us its exact cause or how critical a vulnerability is to your environment.