AI agents hacked Anthropic, maker of arguably the most capable AI models for cyberdefense

Cybersecurity startup Cathedral used AI agents to breach Anthropic's internal systems via third-party business software, reaching meeting transcripts, salary data, job postings and Slack messages, according to a draft report reviewed by The Washington Post. Anthropic confirmed access to a limited set of sales, HR and IT systems but said chats with Claude, source code and model weights were never exposed, and it shut down the access points the same day. The two sides dispute the breach's duration and scope, and Anthropic accuses Cathedral of incomplete disclosure under its bug bounty rules.