As part of the Firefox 39 release, Mozilla is providing 13 security advisories, four of which are rated as being critical. The critical security advisories include MSFA-2015-66 , which provides a patch for seven different identified vulnerabilities (CVE-2015-2734, CVE-2015-2735, CVE-2015-2736, CVE-2015-2737, CVE-2015-2738, CVE-2015-2739 and CVE-2015-2740).
“These [vulnerabilities] included three uses of uninitialized memory, one poor validation leading to an exploitable crash, one read of unowned memory in zip files, and two buffer overflows,” Mozilla warns in its security advisory. “These do not all have clear mechanisms to be exploited through web content but are vulnerable if a mechanism can be found to trigger them.”