Mozilla Thunderbird is a standalone mail and newsgroup client. This update upgrades Thunderbird to version 68.9.0. Security Fix: * Mozilla: Security downgrade with IMAP STARTTLS leads to information leakage * Mozilla: Use-after-free in SharedWorkerService * Mozilla: JavaScript Type confusion with NativeTypes * Mozilla: Memory safety bugs fixed in Firefox 77 and Firefox ESR 68.9 For more details about the security issue, including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page listed in the References section.