Finding a bug in Windows Defender isn’t new, but Microsoft It took me five years to solve one that I already knew Definitely worth mentioning. As many of our readers already know, bugs and failures are common in the software world and can not only be more or less serious, but also have different impacts depending on their own particularities.

We will understand it better with an example. Imagine that Microsoft finds a bug in Windows Defender that occurs when using Chrome. Since this browser is the most used, its scope would be very large, and therefore, even though it is a small problem, the Redmond giant would have reason to rush when it comes to solving it.

Now let’s consider the same example, but with a browser that has a very small user base, Firefox. In this case, it is clear that its impact would be lessand that Microsoft could take it much more calmly, since it would affect a much smaller number of users than in the previous case.

Well, that’s exactly what happened with a bug that Microsoft identified five years ago in Windows Defender and generated high CPU consumption when using the Mozilla Firefox browser. This issue has been active for half a decade, and today we can finally confirm that it has been fully resolved thanks to the joint efforts of the Microsoft and Mozilla development teams.

The solution will be implemented in Integrated update to new definitions of Windows Defenderand therefore will be independent of the operating system-level updates that Microsoft regularly releases for Windows 10 and Windows 11. This update will also reach Windows 7 and Windows 8.1, two operating systems that are no longer officially supported by Microsoft, and that should not theoretically suffer from this failure.

Regarding the dates, I can confirm that the update was deployed on April 4th, so This should be commonly available by now. This is a very important update for anyone using Firefox on Windows with the Microsoft security suite, as this bug caused the browser offered a rather weak performance and that the response time was very slow even for such simple tasks as browsing different web pages and reloading or changing pages.