Mozilla has released Firefox 74 to the Stable desktop channel for Windows, Mac, and Linux desktop users. New features include the Facebook container, the blocking of sideloaded add-ons, and the disabling of TLS 1.0 and 1.1 certificate support. Users can upgrade to Firefox 74.0 by going to Options -> Help -> About Firefox and the browser will automatically check for the new update and install it when available. The other development branches of Firefox have also moved up a version. This brings Firefox Beta to version 75 and the Nightly builds to version 76.
Source: https://www.bleepingcomputer.com/news/software/firefox-74-released-security-fixes-improvements-and-fixes/