Mozilla releases Firefox 66.0.3

Martin Brinkmann
Apr 10, 2019

Mozilla plans to release Firefox 66.0.3, a minor upgrade to the web browser's stable channel, later today on April 10, 2019.

Firefox 66.0.3 is the third minor release after the release of Firefox 66.0 in March 2019. Firefox 66.0.1 was a security update to address new vulnerabilities discovered by participants of the Pwn2Own hacking contest, Firefox 66.0.2 a bug fix release that addressed an issue with certain online editors.

Firefox 66.0.3 will be released later today if the schedule holds. Firefox users may check for updates manually by selecting Menu > Help > About Firefox. Note that the check comes up empty at the time of writing as the new version has not been released officially.

Downloads are already available but it is recommended to wait for the official release announcement.

Firefox 66.0.3

Firefox 66.0.3 is a bug fix release that addresses the following four issues in Firefox Stable:

  • Performance issues with certain HTML5 games on See "Games on are slow because they use an obfuscator that deliberately triggers stack overflow exceptions" bug 1537609 for additional information. Mozilla appears to have received feedback from a large number of users who ran into the issue to warrant a bug fix release.
  • Additional keypress event fixes for select Microsoft cloud applications and IBM cloud applications. Check out "Remove superfluous dot from use_legacy_keycode_and_charcode pref"  bug 1539618 for the Microsoft cloud applications issue and""Enter" key is broken in our IBM Sametime Webchat application when using Firefox 66" bug 1538970 for details on the IBM cloud applications issue.
  • Fixed an issue that affected the Firefox address bar behavior on tablets running Microsoft's Windows 10 operating system. See "Waking up from sleep / switching to tablet mode shows a sticky address bar panel, when Firefox is the default browser" bug 1498973 for additional details.

Firefox 66.0.3 includes an updated Baidu search plugin next to all that.

Closing Words

Firefox 66.0.3 addresses several specific issues that affect some users who use the web browser. There is no hurry to upgrade to the new version if you are not affected by the issues. The next major Firefox release, Firefox 67, is scheduled for a May 14, 2019 release.

Now You: Did you experience any of the issues fixed in the new Firefox version?

Mozilla releases Firefox 66.0.3
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Mozilla releases Firefox 66.0.3
Mozilla plans to release Firefox 66.0.3, a minor upgrade to the web browser's stable channel, later today on April 10, 2019.
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  1. mark ball said on May 4, 2019 at 4:17 am

    honey and,avast password won’t work on it

  2. Antivenum said on May 4, 2019 at 3:38 am

    Every single person here realizes it is only April 3rd right? That his entire thing is 7 days in the future and some of you are posted with a date 13 days later than it is? Trust this site and what it says as you wish knowing that.

    But Firefox just removed every single one of my addons. Including Adblock. Like I am using any browser that doesn’t have that on it.

  3. Big Head said on April 15, 2019 at 4:10 am

    I just deleted Firefox. I thought I would start using it again someday, but I have moved on. It was nice while it lasted, but that was years ago. Goodbye Firefox, and thanks for all the fish.

  4. Siggy62 said on April 14, 2019 at 3:54 pm

    My wife got a new laptop. Downloaded Firefox, now she can’t even get to her banking site. By the way it was just fine in the last release. FAIL!!!

    1. Anonymous said on April 16, 2019 at 5:42 pm

      That’s likely the website’s failure. Try reporting the problem to

      1. Siggy62 said on April 16, 2019 at 5:51 pm

        Oddly, I googled the bank, used the link in google, and it worked fine. Double checked the url and it was the same as I entered. Don’t know what the issue was.

  5. Lakshmi said on April 13, 2019 at 3:31 am

    I’m having site rendering issues under Win10. Sometimes when I scroll pages seem to hang. Other times pages don’t seem to render well and I need to refresh the page or scroll to fix it.

    1. Anonymous said on April 16, 2019 at 5:45 pm
  6. John IL said on April 12, 2019 at 8:28 pm

    I keep wanting to use Firefox and each time I hope its going to be everything I want it to be and its just not. I just tried Edge Chromium developer release and its better as a beta then Firefox in my honest opinion. How can this be I ask myself given how many people work on Firefox all the time? Maybe its time for Mozilla to ask itself if the problems are with their browser at the core parts of it?

  7. user17843 said on April 11, 2019 at 3:12 pm

    In other news: The joint move by Google and Mozilla to censor the dissenter extension from the stores has prompted them to announce a privacy focused Chromium fork:

    1. Lord-Lestat said on April 12, 2019 at 8:11 pm

      There is a small thin line between discriminating Mozilla’s origin power-user ex-target user-base towards discrimination/censorship against free speech/political “incorrect” opinion.

      No surprise here, that was well known since a pretty damn long time. That is what Mozilla is today. No super-hero anymore to save your free valuable web, they are now a super-villain protecting big money and corporate interests.

    2. Yuliya said on April 11, 2019 at 11:35 pm

      I almost feel bad for them:
      Almost, I really don’t because mozilla is absolutely disgusting, borderline vomit inducing every single time I hear this word, and they totally deserve it, but I almost do, as I quite liked FireFox v4 – only second to Opera v12, the true Opera.

      1. user17843 said on April 12, 2019 at 10:58 am

        This kind of attitude is sad because it results in a filter bubble where everything controversial does not exist anymore.

        For example, I was just banned from r/firefox for posting these links:

        Ironically it was in reaction to a post that was telling everyone that people are morally obliged to use Firefox. This moral argument can only exist in an intellectual vacuum.

        When they exercise their power to delete everyone from the conversation that does not conform to their standards, they can then declare that no other truth besides their version of reality even exists.

        The downside is that intellectually stimulating debates no longer exist.

      2. Big Head said on April 15, 2019 at 4:22 am

        Intellectually stimulating debates DO exist. You know, like the ones where they all agree that intellectually stimulating debates no longer exist.

  8. Paul(us) said on April 10, 2019 at 12:13 pm

    No, Not the one! But loving Mozilla for keeping up with day to day life!

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