A hexagon is a six-sided polygon with equal or near-equal sides and angles. In cyber security, the word is mostly used as a visual or design term, not as a threat name: it can describe icons, diagrams, or the structure of a system model. Recognizing the shape correctly matters because security teams rely on clear diagrams to show trust boundaries, data flows, and control points.
Hexagons also appear in hexagonal architecture, a software design pattern that keeps core business logic separate from external inputs such as web requests, databases, and message queues. That separation can reduce the attack surface, make validation and authorization easier to enforce at the edges, and limit the damage if an interface is compromised. Attackers often target weak adapters; defenders use the same boundary-focused design to contain risk.