Entanglement is a fundamental property of quantum mechanics and plays a central role in quantum information science, quantum computation, and many-body physics. It represents non-classical correlations between subsystems that cannot be explained by local hidden variables. Despite its conceptual importance, entanglement remains difficult to quantify in practice because it is not directly observable. Various tools have been developed to estimate entanglement. Among these, a particularly insightful approach is based on the concept of squashed entanglement, a rigorous entanglement measure defined through the quantum conditional mutual information. Specifically, the squashed entanglement of a bipartite state is given by the infimum of the conditional mutual information over all possible extensions.