CWE-bench is designed to test the limits of frontier cyber capabilities. In our continued pursuit to push the horizon at Collinear AI, CWE-bench v2 opens up a public set of 100 tasks that anyone can run and evaluate their models on. The setup is the same as before. An agent gets a checkout of a real open-source repository and a short instruction, with the goal of finding and fixing a security weakness without breaking existing functionality. Scoring is fully programmatic, so results are deterministic and anyone can reproduce them without extra cost. All our programmatic checks have been curated with the help of LLM judge panels that shape them towards the direction of hardness and fairness. We also maintain a held-out set, so that we can keep tracking progress on tasks no model has seen. To evaluate your model on the held-out set, contact cyber@collinear.ai.