A machine-implemented method for controlling a configuration data item in a storage-equipped device having at least two security domains, comprising receiving, by one of the security domains, a configuration data item; storing the configuration data item; providing a security indication for the configuration data item; and when an event indicates untrustworthiness of the data item, invalidating a configuration effect of the stored configuration data item. Further provided is a machine-implemented method for controlling a storage-equipped device as a node in a network of devices, comprising receiving information that a data source or type of a configuration data item is untrusted; analysing metadata for the data source and the configuration data item; populating a knowledge base with analysed metadata; and responsive to the analysed metadata, transmitting security information to the network of devices. A corresponding device and computer program product are also described.