Multiple security issues have been found in the Mozilla Firefox web browser, which could potentially result in the execution of arbitrary code, cross-site scripting or spoofing the origin of a download. Debian follows the extended support releases of Firefox. Support for the 68.x series has ended, so starting with this update we"re now following the 78.x releases. Between 68.x and 78.x, Firefox has seen a number of feature updates. For more information please refer to https://www.mozilla.org/en-US/firefox/78.0esr/releasenotes/