The present paper proposes an accurate characterization of a NACA 23012 airfoil at near stall conditions at a Reynolds number $Re=3\cdot 10^5$. In light of the unavoidable limits of which experiments suffer near the stall regime both in terms of effective two--dimensionality and data portability across different research groups, the present characterization is performed through high fidelity numerical simulations. Taking advantage of the local discontinuous Galerkin (LDG) LES solver, implemented in the open source library \textit{FEMilaro}, the airfoil behavior is investigated ranging from $\alpha=5^{\circ}$ to $17^{\circ}$, with a peculiar focus for $\alpha \ge 10^{\circ}$. Accuracy of the found results is ensured both from the realistic and accurate reconstructed flow physics and by means of a proper comparison with existing experimental data. Then, a reliable numerical baseline is obtained for any future investigation involving a NACA 23012 airfoil at $Re=3 \cdot 10^5$. The future study of the actual research group will be a parallel BVI analysis, but results are completely extendable as they are to any other research.