Open source ctf projects

Every project in the registry tagged ctf, ranked by real GitHub adoption.

projects 3 combined stars ★ 4.6K refresh nightly
01 pentest-ai-agents ★ 2.2K

Turn Claude Code into your offensive security research assistant. Specialized AI subagents for authorized penetration testing plan engagements, analyze recon, r

last push1 months ago languageShell licenseMIT
02 pentest-ai ★ 1.7K

Open-source AI pentester that proves every finding. Machine oracles re-run each exploit; verified bugs ship a proof capsule you can replay yourself.

last push5 days ago languagePython licenseMIT
03 h5i ★ 647

Fast, red-teaming browser built for AI agents, with direct HTTP traffic control, sandboxed execution, and auditable sessions. Pure Rust.

last push26 hours ago languageRust licenseApache-2.0

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Frequently asked questions

How many open source ctf projects are there?

This registry tracks 3 projects tagged ctf, with 4,567 GitHub stars between them. The most-adopted is pentest-ai-agents at 2,242 stars.

Are these ctf projects free to use?

Yes — 3 of the 3 carry an explicit open-source licence across 2 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.

Which ctf project should I choose?

The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.

Are these ctf projects still maintained?

3 of the 3 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.