UK AISI and CAISI Assess Kimi K3's Cyber Capabilities and Exploit Development

UK AISI / Caisi Preliminary Assessment of Kimi K3's Cyber Capabilities

We evaluated Moonshot AI's Kimi K3 model alongside leading U.S. systems using benchmarks like ExploitBench and The Last Ones. While Kimi K3 outperforms previous open-weight models like GLM-5.2, it falls short of frontier U.S. models in complex attack chains. Notably, Kimi K3 failed to achieve arbitrary code execution in our tests, though it did successfully complete a simulated corporate network attack in one out of ten attempts.