When SmartStart Inclusion fails during the onboarding of a Z-Wave PIR sensor, the sensor will join the network as a non-secure device. This vulnerability exists in Silicon Labs Z-Wave PIR Sensor Reference design delivered as part of SiSDK v2025.6.0 and v2025.6.1.
A protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties.