AI agents access Anthropic internal systems via third-party software

Cathedral exploited weaknesses in third-party administrative and sales software to access Anthropic's systems. The company confirmed that Cathedral accessed a limited set of sales, HR, and IT systems. Cathedral's AI agents accessed meeting transcripts, salary and job-offer details, and Slack messages about Anthropic's advanced models. Anthropic stated that customer conversations with Claude, source code, and model weights were not reached. Anthropic shut off Cathedral's access the same day it flagged their activity.

Cathedral claims data accesses were kept to the absolute minimum in accordance with security research best practices. Anthropic accused Cathedral of overstating national security implications and not fully following bug bounty program rules. A senior Trump administration official raised concerns that if Cathedral can do this, Chinese hackers might be close behind. Cathedral used AI agents to infiltrate Anthropic's internal systems through third-party business software as part of Anthropic's bug bounty program.

Cathedral reported finding Slack messages, salary data, and other internal records within hours. Anthropic insists that source code and model weights were never exposed. Cathedral's AI agents found paths to meeting transcripts, salary data, job postings, and Slack messages in under twelve hours. Anthropic confirmed researchers accessed contact information for some customers and partners along with basic user account data. Anthropic shut down the affected access points the same day it found the breach. Cathedral claims the incident took less than twelve hours, while Anthropic says the attempts lasted several days. Anthropic stated that Cathedral only reported one of two vulnerabilities found in third-party software. Former OpenAI employee Will Depue claimed Cathedral gained full admin access to the Slack workspace and could log into any user account. Anthropic disabled the affected software until vendors confirmed fixes. Anthropic notified U.S. federal authorities about the breach.