Entanglement and Rényi entropies provide complete characterisation of entanglement for pure states in bipartite systems. These entanglement measures also encode the universal behaviour of quantum critical points, especially in one dimension. However, these entropy-based entanglement measures fail when the system is in a mixed state. For mixed states separability criterion are studied. While partial transpose criterion has been much studied, the computable cross norm ratio (CCNR) criteria has received much less attention, especially in quantum many body contexts. The mixed state entanglement measures are also known to encode the universal behaviour of quantum critical points. In this talk I'll discuss the computation of Rényi CCNR negativity in compact boson CFT to characterise bipartite mixed state entanglement between multiple disjoint intervals.