It appears you have a (third-party) Ubuntu build of Firefox. If you use your Linux distribution's packaged version of Firefox, you will need to wait for an updated package to be released to its package repository. Firefox 128.0 was only just released as of July 9th. You could use the official builds of Linux Firefox from Mozilla. https://support.mozilla.org/en-US/kb/install-firefox-linux If you use the tarball builds, make sure the Firefox folder has read/write permissions for the user in order to get Firefox update from Mozilla. An easy way is to have the Firefox folder in Home.