Hacktron researchers use Claude Opus 5 to breach OpenAI accounts

Security researchers at Hacktron utilized Anthropic’s Claude Opus 5 model to compromise multiple OpenAI employee accounts and access an internal code repository. The team reportedly chained two distinct vulnerabilities using the large language model to assemble and execute the attack sequence faster than human analysts could document individual steps. According to the disclosure, stolen employee credentials served as the pivot point to reach internal systems, with each hop appearing as an authorized session in isolation. The incident highlights a critical gap in current security tooling, which remains calibrated for human-speed lateral movement rather than automated AI exploitation. Security practitioners now face the challenge of detecting non-human identity chains that cross trust boundaries before internal assets are breached. Neither Anthropic nor OpenAI has publicly commented on the specific technical details or remediation status of this alleged compromise.