A Z-buffer, or depth buffer, is a per-pixel memory area used by a renderer to decide which surface is closest to the camera. When multiple polygons overlap on screen, the renderer compares their depth values and keeps the fragment in front while discarding hidden ones. This is what prevents distant objects from drawing over nearer ones and makes 3D scenes look coherent.
In cyber security, Z-buffer handling matters because it sits inside graphics engines, GPU drivers, browsers, and game clients—software that processes untrusted content at high speed. Malformed models, textures, or shader inputs can trigger bugs in depth calculations or adjacent memory handling, causing crashes, denial of service, or, in rare cases, memory corruption. Defenders look for these issues with fuzzing, strict asset validation, and timely driver updates, because rendering code is often a large and complex attack surface.