Security researchers at Hacktron used Anthropic's Claude Opus 5 to chain a memory corruption flaw in the libheif image-processing library with a weakness in OpenAI's single sign-on system, successfully taking over ChatGPT and Codex accounts belonging to several OpenAI employees and gaining access to an internal code repository. The attack began through OpenAI's public help forum, which used the same login system as internal tools, meaning compromising the forum server granted access wherever that sign-on was trusted. OpenAI patched the vulnerability within 14 hours of being notified and paid a $6,500 bounty, while the researchers note that Claude Opus 5 was critical to the effort, producing a working exploit within hours after the previous model had struggled — illustrating how capable AI is lowering the skill and time required for serious offensive security work.
