Create a PriorityClass with globalDefault true.

Every pod created afterwards with no priorityClassName inherits that priority, cluster-wide.

No pod create verb is needed.

The effect lands on other people's future workloads, not on one the attacker submits.

Existing pods keep the priority they were admitted with, so the change is invisible until the next rollout.

This only works where no global default exists yet.

Admission rejects a second one outright, so displacing an existing default would additionally need delete on it