ClusterFuzz is a scalable fuzzing infrastructure that finds security and stability issues in software.

Google uses ClusterFuzz to fuzz all Google products and as the fuzzing backend for OSS-Fuzz.

ClusterFuzz provides many features which help seamlessly integrate fuzzing into a software project's development process:

• Highly scalable. Can run on any size cluster (e.g. OSS-Fuzz instance runs on 100,000 VMs).
• Accurate deduplication of crashes.
• Fully automatic bug filing, triage and closing for various issue trackers (e.g. Monorail, Jira).
• Supports multiple coverage guided fuzzing engines (libFuzzer, AFL, AFL++ and Honggfuzz) for optimal results (with ensemble fuzzing and fuzzing strategies).
• Support for blackbox fuzzing.
• Testcase minimization.
• Regression finding through bisection.
• Statistics for analyzing fuzzer performance, and crash rates.
• Easy to use web interface for management and viewing crashes.
• Support for various authentication providers using Firebase.

You can find detailed documentation here.

As of February 2023, ClusterFuzz has found ~27,000 bugs in Google (e.g. Chrome). Additionally, ClusterFuzz has helped identify and fix over 8,900 vulnerabilities and 28,000 bugs across 850 projects integrated with OSS-Fuzz.

You can file an issue to ask questions, request features, or ask for help.

We will use clusterfuzz-announce(#)googlegroups.com to make announcements about ClusterFuzz.

For a more lightweight version of ClusterFuzz that runs on CI/CD systems, check out ClusterFuzzLite.