High voltage is an elevated electrical potential used to force current through a circuit or component. In practical terms, it can move enough energy to heat wires, charge capacitors, fire relays, or trigger ignition elements. The key security issue is not just shock risk: high voltage can rapidly change the state of hardware, sometimes in ways that are irreversible.
In cyber security, high voltage matters anywhere attackers or defenders interact with physical systems, including industrial control equipment, embedded devices, and tamper-resistant hardware. It can be used to bypass protections, damage components, or force a device into an unexpected mode. Defenders must treat voltage limits, insulation, isolation, and controlled discharge as part of the trust boundary. When a system depends on a single electrical pulse, the attack surface includes the power path itself, not only software or network access.