GHSA-c3px-v9c7-m734: Prototype Pollution in mithril

The GitHub advisory directly identifies parseQueryString as the vulnerable function. Runtime exploitation would involve this function processing attacker-controlled query parameters. A profiler would show this function actively parsing the malicious payload (e.g., during route handling or AJAX parameter parsing). No other functions are explicitly mentioned in the advisory as being involved in the vulnerability. The lack of prototype pollution checks in the parameter assignment logic is the root cause.