Mozilla Thunderbird is a standalone mail and newsgroup client. This update upgrades Thunderbird to version 78.3.1. Security Fix: * Mozilla: Memory safety bugs fixed in Firefox 81 and Firefox ESR 78.3 * Mozilla: XSS when pasting attacker-controlled data into a contenteditable element * Mozilla: Download origin spoofing via redirect * Mozilla: When recursing through layers while scrolling, an iterator may have become invalid, resulting in a potential use-after-free scenario 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.