Tailgating

Tailgating (or piggybacking) is a physical security breach where an unauthorized person follows an authorized person through a secured door or entrance. The unauthorized person may simply walk closely behind someone who badges in, hold the door and claim they forgot their badge, or carry items that make it seem rude not to hold the door open.

Tailgating bypasses access control systems that rely on badges or key cards. It exploits social norms — people generally feel uncomfortable refusing to hold a door for someone, especially in a professional setting.

Why It Matters

Physical access controls are a CMMC requirement. Tailgating defeats electronic access controls, so additional measures — security awareness, mantrap doors, or security guards — may be needed to prevent unauthorized physical access to CUI areas.