Security startup Hacktron AI used Anthropic's Claude Opus 5 to breach OpenAI through its bug-bounty program, earning a $6,500 award, The Wall Street Journal reported. The team chained two vulnerabilities — a memory bug in the libheif library behind OpenAI's Discourse forum and a second flaw — to access employee ChatGPT and Codex accounts. OpenAI says the issues are resolved. Hacktron noted Opus 4.8 failed the exploit until Opus 5's release succeeded within hours.
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