New Firefox 124 and Thunderbird 115.9 available

The Mozilla Foundation has released the web browser Firefox 124, Firefox ESR 115.9 and the email software Thunderbird 115.9. The most important changes concern the security of the programs, as the developers close security leaks with the updates.

As the Release Notes for Firefox 124 show, the programmers have sealed six high-risk vulnerabilities, five medium-severe vulnerabilities and one security vulnerability classified with a low threat level, making a total of twelve.

In Firefox ESR 115.9, however, six high-risk and four medium-risk vulnerabilities were fixe. The same number as Firefox ESR also seals the Thunderbird 115.9 based on it, according Release Notes show.

The release notes for Firefox 124 show the accessibility features have been improved and now also work in the PDF viewer. Open tabs in Firefox View can now be sorted by most recent activity or by tab order, with the default being most recent activity. In macOS, Firefox now relies on the operating system's fullscreen API to display various types of fullscreen windows.

Since the security gaps, which are classified as high-risk, can usually be used by displaying maliciously manipulated websites to plant malicious code, users should apply the updates quickly. This is done by the version dialog, which opens by clicking on the browser settings menu, which is located behind the symbol with the three strips on top of each other to the right of the address bar, and then proceeding via "Help" - "About Firefox" or "About Thunderbird". At the end, the dialog also asks you to restart the software so that the changes become active.