This update is strongly recommended.
It fixes following security flaws:
But this is not all….
When restarting Firefox to apply the update I was surprised with the message that I cannot install the update because I’m not an owner of the file or do not have administrative privileges…..
After several retries I realized that there is another user logged on my PC and it was using Firefox 🙁 after closing this extra copy update was installed and now I use latest version.