The commit diff shows two critical changes: 1) Replaced raw output of querystring parameter with htmlspecialchars, indicating it was previously vulnerable to reflected XSS. 2) Added htmlspecialchars around errorType parameter handling, which maps to the 'type' input. Both parameters were explicitly listed in the vulnerability description. The third vulnerability (name parameter in locale/index) isn't shown in provided diffs, so it's excluded from high-confidence findings.