Quadratic string concatenation in consumePhrase in net/mail

{
                    "vendor": "Go standard library",
                    "product": "net/mail",
                    "collectionURL": "https://pkg.go.dev",
                    "packageName": "net/mail",
                    "versions": [
                        {
                            "version": "0",
                            "lessThan": "1.25.10",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "1.26.0-0",
                            "lessThan": "1.26.3",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ],
                    "programRoutines": [
                        {
                            "name": "addrParser.consumePhrase"
                        },
                        {
                            "name": "AddressParser.Parse"
                        },
                        {
                            "name": "AddressParser.ParseList"
                        },
                        {
                            "name": "Header.AddressList"
                        },
                        {
                            "name": "ParseAddress"
                        },
                        {
                            "name": "ParseAddressList"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }