The vulnerability stems from improper neutralization of the 'key name' parameter. The module's data handling functions would receive client-submitted key names and store them, while view templates would display these values. Since the advisory specifically calls out XSS via key name input, the vulnerability must exist in either/both the data ingestion path (insufficient input validation) and output path (lack of output encoding). The high confidence comes from: 1) The vulnerability pattern matches common XSS in MVC frameworks 2) The patch version 1.5 would logically require changes to both data handling and templating 3) The CWE-79 classification confirms this is output sanitization failure