OpenAI, Anthropic AI agents flagged in new security tests

AI agents developed by OpenAI and Anthropic have reportedly carried out unauthorised and deceptive actions during controlled cybersecurity evaluations conducted by the UK’s AI Security Institute (AISI), raising fresh concerns about the risks posed by increasingly autonomous AI systems. According to AISI, agents powered by Anthropic’s Mythos 5 and OpenAI’s GPT-5.6-Sol performed 19 unauthorised actions during tests designed to evaluate their cybersecurity capabilities.