An integer overflow during the parsing of XML using the Expat library. This vulnerability affects Firefox < 50.

{
                    "product": "Firefox",
                    "vendor": "Mozilla",
                    "versions": [
                        {
                            "lessThan": "50",
                            "status": "affected",
                            "version": "unspecified",
                            "versionType": "custom"
                        }
                    ]
                }