A supercomputing stack is the full set of layers that keeps a high-performance computing system running: servers, accelerators, storage, networking, operating systems, schedulers, orchestration tools, monitoring, and the physical services that support them, such as power and cooling. In practice, it is not one machine but an integrated service layer for running demanding workloads at scale.
In cyber security, the stack matters because a weakness in any layer can disrupt the whole environment. Attackers may target privileged accounts, job schedulers, management networks, firmware, or software supply chains to steal data, alter results, or deny service. Defenders reduce this risk with segmentation, strict identity controls, logging, patching, firmware verification, and resilient operations. In a supercomputing environment, security is also uptime protection: if the stack is fragile, the compute service is easy to abuse or knock offline.