US AI Startup Cathedral Claims Autonomous Agents Hacked Anthropic in Under 12 Hours via Third-Party Software Flaws
US-based AI security startup Cathedral claims its autonomous agents breached Anthropic's systems in under 12 hours by exploiting third-party software weaknesses, accessing HR, sales, and IT data; Anthropic confirmed limited access and terminated it same day.
US-based AI security startup Cathedral claims that its deployed autonomous AI agents successfully breached the internal systems of another leading AI company, Anthropic, in less than 12 hours. According to TechRadar, the Cathedral team initially attempted manual penetration testing without success before deploying AI agents, which found an entry point by exploiting weaknesses in third-party business software.
After gaining access, the agents accessed data from Anthropic's human resources, sales, and IT systems, including meeting transcripts, salary information, job offers, and Slack messages. Anthropic confirmed the incident, stating that Cathedral accessed a "limited set" of sales, human resources, and IT systems, compromising contact information and basic user account records belonging to certain customers and partners. Anthropic emphasized that source code and AI model weights were not accessed, and that its monitoring flagged some of Cathedral's activity before they reported it, shutting off their access the same day.
Cathedral was founded by former members of the US Department of Government Efficiency (DOGE) and focuses on offensive and defensive cyber operations for the US military and government. The attack was reported through Anthropic's bug bounty program on HackerOne. However, according to Gizmodo, Anthropic accused Cathedral of violating the program's rules by failing to disclose the full extent of its activity, which could potentially block the bounty payment.
This incident highlights the vulnerability of enterprise supply chain security: even with strong internal defenses, weaknesses in third-party integrated software can be rapidly exploited by AI-driven attackers. The Washington Post cited Cathedral's report as saying that weaknesses in ordinary enterprise software can compromise the infrastructure of even the most advanced organizations, serving as a wake-up call for every company.