UK Banks Denied Access to Mythos AI Amid Cybersecurity Concerns

As of May 29, 2026, UK banks still lack access to Anthropic's Mythos AI model, which is crucial for testing cybersecurity defenses. Bank of England Governor Andrew Bailey highlighted that the delay stems from political and licensing issues with the US administration. Meanwhile, OpenAI has offered access to its GPT-5.5-Cyber model to nine UK banks, providing an alternative for cybersecurity testing. The AI Security Institute found both models to perform similarly in simulating cyber-attacks. Concerns persist regarding the potential misuse of Mythos, which has demonstrated advanced capabilities in penetrating corporate networks. The situation reflects a broader challenge in aligning AI access with regulatory frameworks across jurisdictions. The lack of access to Mythos creates a defensive gap for UK banks managing trillions in assets.

Key Points: • UK banks remain unable to access Anthropic's Mythos AI model due to political delays. • OpenAI has stepped in, offering access to its GPT-5.5-Cyber model to nine major UK banks. • Concerns about the misuse of Mythos highlight the need for regulatory frameworks in AI deployment.