A multikernel is a system design in which more than one kernel participates in managing hardware resources on the same machine. Instead of one kernel owning everything, the system splits control across kernels and coordinates them through explicit interfaces. That can be used to separate workloads, reduce contention, or explore new forms of isolation without relying on a traditional hypervisor.
In cyber security, the important issue is trust boundaries. A multikernel adds coordination logic for boot, memory, devices, and inter-kernel communication, and those seams become high-value targets. If the partitioning or synchronization code is flawed, an attacker may be able to disrupt availability, cross isolation boundaries, or influence shared resources. Defenders should treat a multikernel like any other trust anchor: verify the boundary rules, monitor the communication paths, and test failure handling. The concept is not automatically safer than virtualization; it simply moves the security burden into different code and different assumptions.