ZeroMQ is a high-performance messaging library used to move data between processes, services, and machines. It provides socket-based patterns such as request/reply and publish/subscribe, but it is not a security framework. By design, ZeroMQ transports messages and leaves authentication, encryption, authorization, and input validation to the application.
This matters in cyber security because a ZeroMQ endpoint can become part of the attack surface when it is exposed beyond a trusted boundary. If a service accepts attacker-controlled messages and then passes them to a dangerous parser, command handler, or deserializer, the transport itself can help deliver the exploit. Defenders should treat ZeroMQ sockets like network-facing interfaces: bind them narrowly, protect them with mechanisms such as CURVE or other access controls when appropriate, validate every message, and avoid insecure deserialization of untrusted data.