Gemini 3.5 Flash Cyber, announced July 21, 2026 alongside Gemini 3.6 Flash and 3.5 Flash-Lite, was Google's first cybersecurity-specialised Gemini model — built to find and patch critical software vulnerabilities, and deployed inside Google DeepMind's CodeMender agent. Google reported competitive performance on CyberGym, the benchmark for discovering and exploiting software weaknesses in sandboxed environments, at launch.

Unlike its general-purpose siblings, Flash Cyber did not ship to the public API: access was restricted to a limited pilot program for governments and trusted partners, reflecting the dual-use sensitivity of automated vulnerability discovery. The release marked the first time Google spun a domain-specialised variant out of the Flash line, positioning defensive security as its own product track rather than a capability folded into the flagship.