cargo-fuzz

npx skills add trailofbits/skills --skill cargo-fuzz --agent claude-code

Same command for any agent — swap --agent for codex, cursor, copilot.

# cargo-fuzz cargo-fuzz is the de facto choice for fuzzing Rust projects when using Cargo. It uses libFuzzer as the backend and provides a convenient Cargo subcommand that automatically enables relevant compilation flags for your Rust project, including support for sanitizers like AddressSanitizer. ## When to Use cargo-fuzz is currently the primary and most mature fuzzing solution for Rust projects using Cargo. | Fuzzer | Best For | Complexity | |--------|----------|------------| | cargo-fuzz | Cargo-based Rust projects, quick setup | Low | | AFL++ | Multi-core fuzzing, non-Cargo projects | Medium | | LibAFL | Custom fuzzers, research, advanced use cases | High | **Choose cargo-fuzz when:** - Your project uses Cargo (required) - You want simple, quick setup with minimal configuration - You need integrated sanitizer support - You're fuzzing Rust code with or without unsafe blocks ## Quick Start ```rust #![no_main] use libfuzzer_sys::fuzz_target; fn harness(data: &[u8]) { your_project::check_buf(data); } fuzz_target!(|data: &[u8]| { harness(data); }); ``` Initialize and run: ```bash cargo fuzz init # Edit fuzz/fuzz_targets/fuzz_target_1.rs with your harness cargo +nightly fuzz run fu

cargo fuzz init
Edit fuzz/fuzz_targets/fuzz_target_1.rs with your harness
cargo +nightly fuzz run fuzz_target_1
Install nightly toolchain
rustup install nightly
Install cargo-fuzz
cargo install cargo-fuzz
cargo +nightly --version
cargo fuzz --version
cargo +nightly fuzz run --sanitizer none fuzz_target_1