DEF CON's $4M AI Cyber Challenge: What We Learned from the Winners
At DEF CON 33, DARPA’s AI Cyber Challenge showcased autonomous systems finding and patching vulnerabilities faster and more accurately than ever. With top teams like Team Atlanta and Trail of Bits now open-sourcing their tools, AI is now a fundamental ally in critical infrastructure cybersecurity.

A Groundbreaking AI Cybersecurity Milestone
DARPA's two-year AI Cyber Challenge (AIxCC) concluded at DEF CON 33, spotlighting autonomous AI systems capable of detecting and patching vulnerabilities in open-source code– especially code foundational to critical infrastructure. The results? Remarkable.
Meet the Winners & Their Impact
- Team Atlanta (Georgia Tech, Samsung Research, KAIST, POSTECH), secured 1st place and $4 million, with their model achieving top-tier performance on speed, accuracy, and vulnerability coverage. Four of the finalist models are already open-sourced.
- Trail of Bits, dubbed "Buttercup," took 2nd place with $3 million. The system discovered 28 vulnerabilities across 20 CWEs and applied 19 accurate patches– earning praise for economic efficiency in AI queries.
- Theori earned 3rd place and $1.5 million for their high-performing cyber reasoning system.
What the Competition Showed Us
- Finalists discovered 77% of injected vulnerabilities and patched 61%, with average response times around 45 minutes. Additionally, they uncovered 18 real zero-day flaws across C and Java codebases
- This year's performance showed dramatic improvement from last year's semifinals finding only 37% underscoring the rapid maturation of AI in cyber defense.
- AIxCC isn't just theoretical– organizations now have open-source cyber reasoning systems (CRS) that can integrate into real-world infrastructure, especially in health, water, and energy sectors.
- DARPA, along with ARPA-H, is investing an additional $1.4 million to drive commercial and critical infrastructure deployment of these AI tools.
ThreatGrid Takeaways
- AI systems are not just detecting bugs– they're starting to auto-patch at scale, in real time.
- Open-source CRSs from AIxCC offer a refreshingly transparent and accessible defense option for resource-constrained sectors.
- Alert to the pace of AI development– solutions have doubled in effectiveness within a year.
- Infrastructure and software security is entering a new era of AI-empowered resilience.