Developers rely on software ecosystems such as Maven to manage and reuse external libraries (i.e., dependencies). Due to the complexity of the used dependencies, developers may face challenges in choosing which library to use and whether they should upgrade or downgrade a library. One important factor that affects this decision is the number of potential vulnerabilities in a library and its dependencies. Therefore, state-of-the-art platforms such as Maven Repository (MVN) and Open Source Insights (OSI) help developers in making such a decision by presenting vulnerability information associated with every dependency. In this paper, we first conduct an empirical study to understand how the two platforms, MVN and OSI, present and categorize vulnerability information. We found that these two platforms may either overestimate or underestimate the number of associated vulnerabilities in a dependency, and they lack prioritization mechanisms on which dependencies are more likely to cause an issue. Hence, we propose a tool named VulNet to address the limitations we found in MVN and OSI. Through an evaluation of 19,886 versions of the top 200 popular libraries, we find VulNet includes 90.5% and 65.8% of the dependencies that were omitted by MVN and OSI, respectively. VulNet also helps reduce 27% of potentially unreachable or less impactful vulnerabilities listed by OSI in test dependencies. Finally, our user study with 24 participants gave VulNet an average rating of 4.5/5 in presenting and prioritizing vulnerable dependencies, compared to 2.83 (MVN) and 3.14 (OSI).