The vulnerability description points to a specific file and argument (Name) in Apereo CAS 5.2.6, related to inefficient regular expression complexity. However, attempts to fetch the relevant file content for this version and the commits associated with the v5.2.6 tag failed. Without access to the source code or specific patch details, it's impossible to identify the exact vulnerable functions, their signatures, or the precise code changes that constitute the vulnerability or its fix. The available information from VulnDB and NVD describes the vulnerability at a high level but does not provide the necessary code-level details for this analysis.