OpenAI’s new GPT-5.5-Cyber just beat Mythos 5 on CyberGym.
Rohan Paul Twitter · Rohan Paul (@rohanpaul_ai) · 2026-06-22
OpenAI's GPT-5.5-Cyber model tops the CyberGym benchmark by surpassing Mythos 5, signaling strong capability for AI-assisted defensive vulnerability analysis of known software weaknesses.
Extraction
Topics: ai-cybersecurityai-benchmarksopenai-models
Claims
- OpenAI's GPT-5.5-Cyber beat Mythos 5 on the CyberGym benchmark.
- CyberGym measures whether an AI agent can reproduce known software vulnerabilities.
- The benchmark result is a strong signal for the model's utility in defensive vulnerability analysis.
- OpenAI launched a major push to deploy GPT-5.5-Cyber alongside the benchmark result.
Key quotes
CyberGym measures whether an agent can reproduce known software vulnerabilities, so this is quite a strong signal for defensive vulnerability analysis of models.