OpenAI's Mythos vs GPT-5.5-Cyber cyberattack simulation gap widens by Q4 2026

By December 31, 2026, GPT-5.5-Cyber will outperform Mythos in completing simulated corporate cyberattacks by a margin of at least 15%. OpenAI's optimization for cybersecurity workflows will drive measurable performance gains.

Implied probability (Yes)

65%