Yeah, exactly. People tend to misunderstand fuzzing, and think of it as "feeding random garbage at an API". Fuzzing, done with proper tooling, is automated coverage testing. You have a bounds overflow that depends on input data but only if condition A and B and C are true in the runtime state? Fuzzing will find it, almost always, by detecting the branching behavior of your code.

So all the replies here saying "the tests didn't find it because they didn't cover the case" are missing the point. There are test paradigms that don't rely on humans to enumerate cases.