We present the study of the non-linear stability of a class of travelling-wave solutions to the compressible pressureless Navier-Stokes system with a singular viscosity. These solutions encode the effect of congestion by connecting a congested left state to an uncongested right state. By using carefully weighted energy estimates we are able to prove the non-linear stability of viscous shock waves to this system under a small zero integral perturbation, which in particular extends previous results that do not handle the case where the viscosity is singular. This is a joint work with Muhammed Ali Mehmood from Imperial College, London.