A startup's AI agents reached a limited set of Anthropic's sales, HR and IT systems through third-party business software in under 12 hours

Cathedral (co-founders Gavin Kliger, Luke Farritor, Marko Elez, Jack Stein); Anthropic; unnamed third-party software vendors

The Washington Post reported on Oct 26, per Gizmodo and Cyber Security News, that the months-old security startup Cathedral used AI agents to find routes into Anthropic's internal systems in under 12 hours, after several days of failed attempts against Anthropic's own software. The agents went through weaknesses in unnamed third-party business software used for sales and administration. Anthropic confirmed access to a 'limited set' of its sales, HR and IT systems holding business contact details for some customers and partners and basic user account records, and says customer prompts, Claude responses, source code and model weights were not accessed. Cathedral's draft report says its paths reached meeting transcripts, salary and job-offer details and internal Slack discussions, and calls the findings 'a wake-up call for every company in America'. The work ran under Anthropic's outside-researcher programme; Anthropic says Cathedral did not fully follow its bug-bounty rules because it did not disclose all of its activity, while Cathedral says it kept data access to the minimum needed. Anthropic says its monitoring flagged some of the activity before Cathedral reported it, it cut access the same day, disabled the affected software until vendors confirmed fixes, and found no evidence anyone else used the weaknesses. The AI models Cathedral's agents ran on are not named.