ext/intl/msgformat/msgformat_format.c in PHP before 5.6.26 and 7.x before 7.0.11 does not properly restrict the locale length provided to the Locale class in the ICU library, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a MessageFormatter::formatMessage call with a long first argument. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-7416
