I was browsing the web and a nice pop-up window indicated that there was an update to FireFox which then prompted me to download and install the new version of the browser.
According to the website PC Advisor the main reason for the early update was due to one major bug although they classify it as being minor.
Mozilla said that the patched bug, though rated as a low threat, could be used by attackers to run a rudimentary port scan of systems within the same perimeter as the victimized machine. The attacker, however, would have to craft a malicious website and host it on an FTP server and then con users into visiting the page.
Interesting nonetheless and you should always update your browser to the newest available version if at all possible. You never know as this fix may save you from being affected by the fixed bug in FireFox 188.8.131.52.