Security firm Trail of Bits has open-sourced Buttercup, a Cyber Reasoning System (CRS) developed for the AIxCC (AI Cyber Challenge).
It is designed to find and patch software vulnerabilities in open-source code repositories.

Buttercup is now open-source!
Now that DARPA’s AI Cyber Challenge (AIxCC) has officially ended, we can finally make Buttercup, our CRS (Cyber Reasoning System), open source!

The Trail of Bits Blog (blog.trailofbits.com)
GitHub - trailofbits/buttercup
Contribute to trailofbits/buttercup development by creating an account on GitHub.
GitHub (github.com)