This update fixes the following critical security issues: * use-after-free vulnerabilities that could lead to code execution (CVE-2017-3058, CVE-2017-3059, CVE-2017-3062, CVE-2017-3063). * memory corruption vulnerabilities that could lead to code execution (CVE-2017-3060, CVE-2017-3061, CVE-2017-3064).