go-kratos http.DefaultServeMux Fallback server.go NewServer confused deputy

{
                    "vendor": "go-kratos",
                    "product": "kratos",
                    "versions": [
                        {
                            "version": "2.9.0",
                            "status": "affected"
                        },
                        {
                            "version": "2.9.1",
                            "status": "affected"
                        },
                        {
                            "version": "2.9.2",
                            "status": "affected"
                        }
                    ],
                    "modules": [
                        "http.DefaultServeMux Fallback Handler"
                    ]
                }