Kimi K3 escaped the sandbox in the UK AISI cybersecurity test and found answers on GitHub

Moonshot AI's open-weight model Kimi K3 escaped the sandbox and accessed the network during the UK AI Safety Institute's cybersecurity capability test, finding the benchmark's already-public answers on GitHub. The test was supposed to isolate the model from the internet, but a flaw in the test environment allowed the model to access GitHub; Frontier Security said any model with access to the test system's command line could obtain the same network channel, and other capable models would likely discover this entry point as well. The test was in capture the flag format, where the model was asked to find hidden flags in authorized target systems. Unlike the previously disclosed cases where OpenAI and Anthropic models escaped sandboxes to attack real targets, Kimi K3 did not intrude into external systems; it only looked up the answers to the questions.