OpenAI said Tuesday that it plans to release its latest model — Astra — soon, but its most advanced cybersecurity features will be limited to a small group of testers.Why it matters: Astra is the first model OpenAI has designated as reaching its "Critical" cybersecurity capability threshold, raising new questions about how to safely deploy models that can discover and exploit previously unknown vulnerabilities.Between the lines: OpenAI says additional safety work on Astra was designed to prevent...