We present in this paper a new approximate Godunov solver called WFRoe which aims at enforcing the stability of the approximate Riemann solver VFRoe-ncv. In order to assess the method, we consider extreme situations and thus focus on the computation of some two-phase models which enable to account for flows highly loaded with particles. We show that the new solver WFRoe enables the computation of the propagation of shock waves over near-vacuum, and computes admissible states at each cell interface. Numerical tests confirm the efficiency of the scheme.