› At the start of 2026, "AI in cybersecurity" mostly meant an assistant helping write a detection rule.
› By November, it meant an automated agent pipeline churning out nearly a thousand Linux kernel exploits in ten days, and three major labs keeping their most potent models locked behind verified doors.
› The launch of GPT-6 Cyber provides a clear point to map how this pivotal year unfolded.
› This overview draws on ongoing reporting throughout the year and official disclosures from the AI labs.