Researchers Say They Used Anthropic's Claude AI to Breach OpenAI Employee Accounts

A team of three independent security researchers at a firm called Hacktron used Anthropic's Claude Opus 4.8 and 5 artificial intelligence models to hack into OpenAI employee accounts, The Wall Street Journal reported, as first relayed by The Verge.

According to the report, the researchers completed the breach in less than 72 hours. The access reportedly allowed them to reach OpenAI's internal GitHub repository, referred to internally as "Monorepo."

The Verge, citing the Journal's report, described the repository as containing what was called "OpenAI's algorithmic secrets," though further details on the nature or sensitivity of that material were not specified in the available reporting.

The incident highlights a notable dynamic in the AI industry: a rival company's AI model, Anthropic's Claude, was reportedly used as a tool to penetrate the security defenses of OpenAI, one of Anthropic's chief competitors in the development of large language models.

It remains unclear from available reporting what specific vulnerabilities the researchers exploited, whether OpenAI has since patched the security gaps involved, or what the researchers' stated purpose was in conducting the exercise. The Verge's report did not indicate whether the activity was authorized by OpenAI as part of a security assessment or was conducted independently by Hacktron.

Neither OpenAI nor Anthropic's specific responses to the incident were detailed in the initial reporting. This is a developing story, and further details may emerge as OpenAI, Anthropic, and Hacktron are approached for comment.