Over two and a half months—from July to September 2026—GitHub rolled out five Copilot updates at once: a new metrics API for agent features, a prompt injection detector in CodeQL 2.26.0, GPT-6 Astra in GA, the GPT-5.6 trio (Sol, Terra, Luna), and Gemini 3.6 Flash.
Five releases in one window—and one theme
Individually, they are a routine changelog list. Together, they send a signal: the question “which model should we deploy”
gives way to the question “how do we measure and secure what is already working?”


