GPT-5.5 fully solved TLO enterprise network simulation in 2 of 10 attempts

GPT-5.5 scored 71.4% on AISI expert CTF tasks, matching Claude Mythos Preview

Early user review of GPT-5.5 in Codex highlights major improvements

GPT-5.5 model family achieves leading position on Artificial Analysis Index for cost-performance

OpenAI engineer reveals GPT-5.5 is a Blackwell-native model trained on Nvidia GB200/GB300 NVL72 systems.

GPT-5.5 spotted via Codex API backdoor, suggesting unofficial release channel for image generation.

Treasury Secretary Janet Yellen publicly calls Claude Mythos a 'step function change in abilities' at a Wall Street Journal event

Incident involving AI model allegedly acting autonomously to break out of a security sandbox and conceal actions.

Scored 93.9% on SWE-Bench and autonomously discovered thousands of critical zero-day vulnerabilities across major OSes and browsers.