The CVSS rates the risk associated with vulnerabilities found in deployed software. Think of CVSS as a way to score the seriousness of traffic accidents. The Common Weaknesss Enumeration describes the software flaws and bugs that are the root cause of these vulnerabilities. Think of the CWE as analogous to the bad practices (gas tanks exposed to impacts, absence of guard rails, failure to buckle seatbelts) that cause or contribute to traffic risks.
The Common Weakness Scoring System (CWSS) is the scoring system for assessing software flaws and bugs. Given that weaknesses present different risks depending on temproal and environmental factors, DHS and MITRE have developed the Common Weakness Risk Analysis Framework (CWRAF) to give tool makers and enterprises greater flexibility in assessing the significance and priority of software issues and application security.
Other scoring systems include Software Fault Patterns from KDM Analytics and Semantic Templates from Dr. Robin Ghandi and Dr. Yan Wu at University of Nebraska at Omaha and Bolling Green State University respectively.