Cooperative adaptive cruise control (CACC) is a cooperative intelligent transport systems (C-ITS) function,which especially when used in platooning applications, possess many expected benefits including efficient road spaceutilization and reduced fuel consumption. Cut-in manoeuvres in platoons can potentially reduce those benefits, and are notdesired from a safety point of view. Unfortunately, in realistic traffic scenarios, cut-in manoeuvres can be expected, especiallyfrom non-connected vehicles. In this paper two different controllers for platooning are explored, aiming at maintaining thesafety of the platoon while a vehicle is cutting in from the adjacent lane. A realistic scenario, where a human driver performsthe cut-in manoeuvre is used to demonstrate the effectiveness of the controllers. Safety analysis of CACC controllers usingtime to collision (TTC) under such situation is presented. The analysis using TTC indicate that, although potential risks arealways high in CACC applications such as platooning due to the small inter-vehicular distances, dangerous TTC (TTC < 6seconds) is not frequent. Future research directions are also discussed along with the results.