Cyber attacks cause great damage to our national security, ranging from individual internet user to biggest governmental/industrial organizations, such as Equifax (Data Breach 145.5 Million Accounts, reported in July 2017) or Uber (Data Breach 57 Million Records, reported in November 2017). The cyber assault has significantly increased in breadth and depth. This paper introduces CVExplorer, a novel interactive system for visualizing cybersecurity threats reported in the National Vulnerability Database. The proposed system aims to work as a reporting and alerting tool that can help enhance the security against cyber attacks can potentially reduce network vulnerabilities. The CVExplorer system containing multiple linked views allows users to visualize the relationships of various dimensions in the large number of vulnerability reports, such as types and levels of vulnerability, vendors, and products. The CVExplorer provides an intuitive interface and supports a range of interactive features, such as filtering and ordering by vulnerability severity ratings, allowing users to narrow down topics of interest quickly. To demonstrate the effectiveness of the proposed system, we demonstrate the CVExplorer on two case studies of Common Vulnerabilities and Exposures retrieved from the National Vulnerability Database.