Cascade risk is the chance that a disruption in one service spreads into other connected sectors or operations. In cyber security, this matters because modern infrastructure is tightly interdependent: a problem in one OT, IT, or utility network can affect power, water, transport, communications, fuel, or logistics. The original event may be narrow, but the operational impact can grow as dependent systems lose visibility, control, or support.
Attackers can exploit cascade risk by targeting a high-value dependency such as remote access, a shared vendor connection, or a controller that many processes rely on. Defenders reduce it by mapping dependencies, segmenting networks, limiting privileged access, and planning manual fallback procedures. In practice, good monitoring and recovery planning help keep a local outage from becoming a broader service failure.