AI agents breached Anthropic's internal systems in under 12 hours via third-party software

Researchers from cybersecurity startup Cathedral exploited weaknesses in third-party administrative and sales software to access Anthropic's internal systems within 12 hours. Anthropic confirmed that a limited set of sales, HR, and IT systems were reached, but emphasized that customer conversations, Claude responses, source code, and model weights were not accessed. Cathedral and Anthropic dispute the severity and scope of the breach.