Claude Opus 5 Helped Researchers Take Over OpenAI Staff Accounts via Chained Flaws

Claude Opus 5 Helped Researchers Take Over OpenAI Staff Accounts via Chained Flaws Swati KhandelwalSep 19, 2026Vulnerability / Artificial Intelligence Three researchers at the security firm Hacktron used Anthropic's Claude Opus 5 to chain two flaws and take over the ChatGPT and Codex accounts of several OpenAI employees, then reach an internal OpenAI code repository. The chain began with a bug in the software that runs OpenAI's public help forum and moved through a weakness in OpenAI's own login system. This was security research, not a real-world attack: the team reported the flaws to OpenAI, proved the access with a harmless pull request, and then stopped. From the first look, that internal access took under 72 hours. OpenAI confirmed a…