Google's American Fuzzy Lop is a brute-force fuzzer coupled with an exceedingly simple but rock-solid instrumentation-guided genetic algorithm. afl++ is a superior fork to Google's afl. It has more speed, more and better mutations, more and better instrumentation, custom module support, etc.
98ef9d9a1eee10b1642067700a3ea2ff87ee7aa6ca4a15cb924053c41d119423