honggfuzz

honggfuzz is an open-source, general-purpose fuzzer designed to automatically discover security vulnerabilities in software by performing coverage-guided mutation of input data. It targets compiled binaries, network services, and other software that reads structured input. The tool uses code coverage information gathered from the target to steer input mutations toward untested paths, thereby increasing the likelihood of triggering bugs.

honggfuzz can operate in several modes. It supports instrumentation-based fuzzing through compiled builds that expose coverage data, and it can work alongside sanitizers such as AddressSanitizer and UBSan to detect memory corruption and other bugs. It supports multi-architecture builds and runs on common platforms including Linux, Windows, and macOS. The fuzzing engine includes input mutation strategies, a persistent mode to reduce startup overhead, seed corpora to bootstrap exploration, and crash/hang detection with repro generation.

Users run honggfuzz against a harness that reads input from a file or pipe; the tool executes the target with mutated inputs, monitors for crashes or timeouts, and records unique crashes along with failing inputs for later analysis.

honggfuzz is part of the family of coverage-guided fuzzers alongside AFL and libFuzzer. It is used in research and development to test software for robustness and security defects. The project is maintained as open source with ongoing updates and community contributions.