The document discusses tracking vulnerable JAR (Java archive) files. It notes that many Java applications rely on large numbers of library dependencies, and over 26% of downloads from a popular repository contain known flaws. The author describes a solution used at Red Hat that involves generating a manifest of all JARs used in products, matching this against a database of known vulnerabilities, and enforcing checks for vulnerable files during the build process. This solution uses three components: a tool to generate JAR manifests, a shared vulnerabilities database, and a plugin to check for vulnerabilities during the maven build process.