A system and method for comprehensive cybersecurity threat assessment of software applications based on the totality of vulnerabilities from all levels of the software supply chain. The system and method comprising analyzing the code and/or operation of a software application to determine components comprising the software, identifying the source of such components, determining vulnerabilities associated with those components, compiling a list of such components, creating a directed graph of relationships between the components and their sources, and evaluating the overall threat associated with the software application based its software supply chain vulnerabilities.