Software vulnerabilities is an active area of research, but little is known about how publicly-observable properties of open source software projects and developer communities relate to the time taken to discover and fix vulnerabilities in the projects’ software. This thesis examines that relationship using data harvested from online sources about a sample of 60 open source content management system (CMS) projects and 1268 vulnerabilities affecting the software produced by those projects. Combining project release histories with metrics from two online databases provided reliable proxy dates for vulnerability introduction and fix, but not discovery. Higher commit density (a proxy for project activity) was associated with shorter time of exposure. The lifecycle model, data collection workflow, and software scripts will enable researchers to replicate and extend this analysis, and the evidence-based recommendations provided here will enable improvements to the coverage, quality, access, and integration of online sources for project and vulnerability metrics.