GraphQL is an API query language and runtime that lets clients request and modify data through a single endpoint. Instead of fixed responses, a client can ask for only the fields it needs, which makes APIs efficient for web apps, mobile apps, and automation. The same flexibility also makes GraphQL a high-value security boundary: one endpoint can expose many operations, often across different data types and permissions.
In real attacks, GraphQL is often targeted for schema discovery, data overfetching, and authorization flaws in individual resolvers or fields. If access checks are missing or inconsistent, an attacker may read or change data they should not reach. Defenders reduce risk by enforcing authorization on every field, limiting introspection in sensitive environments, monitoring unusual queries, and applying rate limits and patching quickly. In security reviews, GraphQL should be treated as part of the perimeter, not just a convenience layer.