ZeroMQ is a lightweight messaging library for fast communication between processes or over a network. It provides socket-like APIs and common messaging patterns such as request/response, publish/subscribe, and pipelines, which makes it popular in high-performance services, distributed systems, and helper daemons.
In cyber security, ZeroMQ matters because it can turn an internal component into a network-reachable attack surface. If a service bound to a ZMQ socket accepts untrusted messages, any parser, serializer, or command handler behind that socket becomes a potential target for input-based exploits, including remote code execution through unsafe deserialization or logic flaws. Defenders should treat ZMQ endpoints like any other exposed service: limit network access, require authentication where possible, enable encryption and peer verification, and avoid passing attacker-controlled data into dangerous deserializers or privileged handlers.