Command line used to find this crash: afl-fuzz -i in/ -o out/ ccextractor/linux/ccextractor @@ 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 50.0 MB. 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 drop me a mail at <lcamtuf@coredump.cx> once the issues are fixed - I'd love to add your finds to the gallery at: http://lcamtuf.coredump.cx/afl/ Thanks :-)