Command line used to find this crash: afl-fuzz -U -t 5000 -o /fuzz/fuzz_output/ -i /fuzz/input/ -S 02 -- python3 fuzzer.py @@ If you can't reproduce a bug outside of afl-fuzz, be sure to set the same memory limit. The limit used for this fuzzing session was 0 B. Need a tool to minimize test cases before investigating the crashes or sending them to a vendor? Check out the afl-tmin that comes with the fuzzer! Found any cool bugs in open-source tools using afl-fuzz? If yes, please post to https://github.com/AFLplusplus/AFLplusplus/issues/286 once the issues are fixed :)