Cybersecurity Startup Cathedral Says AI Agents Breached Anthropic's Internal Systems

Cathedral, a cybersecurity startup founded by former members of the Department of Government Efficiency (DOGE), said its AI agents found a way into Anthropic's internal systems in less than 12 hours by exploiting vulnerabilities in third-party business software. The startup said the agents accessed sensitive information including meeting transcripts, salaries, job offers, and Slack messages.

Anthropic confirmed that the researchers accessed a "limited set" of its sales, human resources, and IT systems, including business contact information for customers and partners and some basic user account records, but did not access Claude user conversations, source code, or AI model weights. Anthropic also said the researchers had previously spent several days unsuccessfully trying to breach its software directly.

The activity was part of Anthropic's cybersecurity testing program, which rewards researchers for finding vulnerabilities. Anthropic, however, accused Cathedral of violating the program's rules by failing to disclose the full extent of its activity.

According to reports, Cathedral was founded by Gavin Kliger, Luke Farritor, Marko Elez and Jack Stein, and is focused on AI-driven cybersecurity for military applications. The company has been valued at $1.4 billion and raised $160 million from investors including Andreessen Horowitz and Sequoia Capital.

Anthropic is one of the leading AI labs in the United States, developing advanced large language models that are widely used by businesses, governments, and individuals.