The article gives a literature overview of the current challenges connected with the implementation of the newest IT sourcing models. In the dynamic environment, organizations are required to build their competitive advantage not only on their own resources, but also on resources commissioned from external providers, accessed through various forms of sourcing, including the sourcing of IT services. This paper presents chosen aspects of knowledge management and knowledge and information security, in the context of IT sourcing models implementation. IT sourcing solutions are presented, as employed by modern companies, together with potential benefits offered. The main focus is put on the determination of the most important risks involved in knowledge sharing in IT sourcing relations, as well as minimization and reduction of such risks, with particular attention to the newest trend in IT sourcing - cloud computing services on offer.