OpenAI Previews GPT-5.6 Sol With Restricted Access and Stronger Cyber Safeguards

OpenAI released three GPT-5.6 variants (Sol, Terra, Luna) in a limited preview for U.S. government engagement. Sol is the most powerful version, described as the most capable model yet for cybersecurity, competitive with Anthropic Mythos Preview on ExploitBench using one-third the output tokens. The goal is to enable defensive use while blocking offensive activity.