Kimi K3 trails frontier US models by a wide margin on cyber exploits, and distillation may explain why

The British AI Security Institute (UK AISI) and the U.S. Center for AI Standards and Innovation (CAISI) jointly evaluated Moonshot AI's latest model, Kimi K3.

Kimi K3 trails the leading U.S. frontier models by a wide margin on offensive cyber tasks but outperforms China's GLM-5.2, setting a new benchmark among open-weight models. Its safeguards didn't block exploit development or offensive cyber operations, and the model assisted with both without pushback.

Kimi K3 can't crack the hardest exploit levels

The institutes used ExploitBench, a benchmark developed by Carnegie Mellon University, to test exploit development skills. It uses 41 vulnerabilities found in Chrome's V8 engine after 2023 to track how far a model advances through the software exploitation process. The leading U.S. models averaged 76.2 percent, compared with 32.2 percent for Kimi K3 and 24.4 percent for GLM-5.2.

Kimi K3 scored 32.2 percent on the ExploitBench benchmark, while the leading U.S. models reached 76.2 percent. GLM-5.2 trails at 24.4 percent. | Image: UK AISI / CAISI