Mozilla has released Firefox 104.0 as well as Firefox ESR 102.2 and Firefox ESR 91.13.0. The developers fixed several vulnerabilities and other bugs. In addition, they have optimized the browser's resource and energy consumption.

The Firefox 104 update fixes at least six security vulnerabilities, most of which Mozilla identifies as high risk. Two vulnerabilities, one of which only affects the Android browser, are classified as low risk. Mozilla only lists vulnerabilities found internally without specifying their number. According to Mozilla, these could potentially be exploited to inject and execute code. Attacks on Firefox vulnerabilities are currently not known.

What's new in Firefox version 104

Mozilla has integrated the profiler into the developer tools. It can analyze the processor and graphics unit power consumption caused by Firefox. However, this only works under Windows 11 and Macs with an M1 processor.

Firefox reduces its power and resource consumption when the browser is minimized or running in the background. This works in the same way as before with background tabs.

If you have already installed Firefox, it is best to use the update function integrated in Firefox. This will automatically provide you with the update Firefox 104 as soon as it is available for your Firefox.

You can download the latest version here.

Firefox on UpdateStar | Download

Firefox ESR

Version 102.2.0 of the new Firefox ESR 102.x generation released in June received its second security update. The developers have plugged at least five vulnerabilities which Mozilla also closed in Firefox 104. Internally detected memory corruption could be exploited to execute injected code.

The update to Firefox ESR 91.13.0 fixes at least three vulnerabilities, all of which are considered high risk. They are among the vulnerabilities that Mozilla also fixed in Firefox 104. This is the last update for Firefox ESR 91.x. If you are still using this version branch, prepare for the switch to the new generation 102.x, which will take place in September at the latest. An updated Tor Browser for Windows, macOS and Linux, based on Firefox ESR 91.13.0, will be available soon.

Thunderbird

With the latest update for the 91.x generation of the Thunderbird mail program to version 91.13.0, the MZLA developers have eliminated at least three vulnerabilities that the mail program inherited from Firefox in particular.

Firefox code is used for HTML processing, among other things. Thunderbird 102.2 is a new update for the new mailer generation introduced in June. Five or more vulnerabilities are fixed here. There are also some bug fixes. The switch from Thunderbird 91.x to 102.x via automatic update has been possible for about two weeks.