Request isolation is the separation that prevents one user’s web request, session, or response from affecting another’s. A server should keep each user’s identity and data tied to the correct request, rather than accidentally reusing or exposing them across users.
This boundary matters for confidentiality and access control. In real attacks, a flaw in request handling can expose one user’s information to another or let an attacker interfere with another user’s activity. Defenders reduce the risk by patching server software, reviewing configuration and session handling, and testing that concurrent requests remain separate.