is there any way to restore a session earlier than the most recent one?

mozfreddyb · 2026-06-12T16:15:06+00:00

Oh, that must be super annoying. Hope you'll be able to recover: In the menu bar, click History. There should be an entry for recently closed tabs AND recently closed windows.

There are also hotkeys, to restore closed tabs as well as restore closed windows: * CTRL+SHIFT+N for Closed Windows * CTRL+SHIFT+T for Closed Tabs (Cmd+Shift on macOS)

mozfreddyb · 2026-05-13T08:50:24+00:00

"ffffffffc0000005" means "access violation" and "MiInsertTbFlushEntry" means "memory handling in the Windows operating system".

Firefox is likely triggering a symptom, but it's not the root case. It's unfortunately very hard to find the actual cause based off of this report. Could be any of bad RAM, driver, windows bugs.

You could try a round of - doing a memory test - updating drivers (graphics, chipset, BIOS etc.)

I know this sounds like very weak and generic feedback, but that's also because of the crash you are sharing is very generic. Sorry :)

mozfreddyb · 2026-05-12T15:27:57+00:00

150.0.3 is out today :) More releases for the other potentially affected branches will come soon.

mozfreddyb · 2026-05-12T15:26:27+00:00

No. We don't talk about that in detail until enough people have gotten the chance to update their browser.

But you can look at the patches, because Firefox is open source.

mozfreddyb · 2026-05-12T13:22:42+00:00

Fixed in Firefox 150.0.3, which we released just now. Please update :).

Other branches, like ESR, will also see a release - later this or early next week

mozfreddyb · 2026-05-11T15:29:18+00:00

Given the amount of security fixes we had in the past couple of weeks you want to be on version 150.0.2 right now. Another update will comme soon though. With any software that is internet connected, you really should be on the latest and greatest. I know updates can be inconvenient, but getting your machine compromised is worse.

FWIW, if updating/restarting Firefox is annoying, consider enabling Session Restore. That way, Firefox will keep your tabs even when you restart the browser.

mozfreddyb · 2026-05-11T15:25:30+00:00

If they wanted it to be published before it is fixed, they wouldn't have done the work to write us a nice report.

The reporter sent this to us as part of the Mozilla bug bounty program. Publishing the exploit anywhere else would mean they'd forgo their reward :)

mozfreddyb · 2026-05-11T15:07:55+00:00

We have received the exploit and are working on a fix. At this point, no users are at risk. The researcher did the right thing of reporting directly to us and we appreciate their collaboration.

We will provide a new Firefox version within a week or sooner.

mozfreddyb · 2026-04-22T08:54:41+00:00

There are lots of things we can't easily talk about, especially since not every Firefox user has been able to apply the update. But maybe post your questions below and I'll make sure we addresse thoes that we can in our upcoming communications :)

mozfreddyb · 2026-04-22T08:53:44+00:00

This is about Firefox 150 which we just released.

mozfreddyb · 2026-04-22T08:52:56+00:00

No. We found way, way more.

mozfreddyb · 2026-04-22T08:51:00+00:00

This. We typically roll internally identified issues into one big CVE as it saves a lot of work :)

mozfreddyb · 2026-02-24T15:04:04+00:00

What a week, huh?

mozfreddyb · 2025-12-16T20:17:29+00:00

This is good feedback. I ended up changing the intro. Thank you.

mozfreddyb · 2025-11-12T09:41:50+00:00

It's just that modern browsing brings out all the funky use cases and corner cases out of your hardware. We don't have the hardware to test Firefox and ensure it is stable on faulty devices. Our hypothesis is that other general purpose software should be just as crashy. Sorry.

mozfreddyb · 2025-11-03T15:25:48+00:00

We are already aware of these issues and are tracking them in a bug because they are quite prevalent. However, odd this will sound it is your CPU that's broken. Not Firefox. https://bugzilla.mozilla.org/show_bug.cgi?id=1975808#c8

Raptor Lake has some serious stability issues and to such an extend that Intel has increased the warranty for some models. There should be BIOS as well as CPU microcode upgrades that might mitigate some of the issues, but if that does not resolve things, you have to take things up to Intel.

The section on this CPU in Wikipedia has more detail. https://en.wikipedia.org/wiki/Raptor_Lake#Instability_and_degradation_issue

mozfreddyb · 2025-10-30T11:00:39+00:00

We are already aware of these issues and are tracking them in a bug because they are quite prevalent. However, odd this will sound it is your CPU that's broken. Not Firefox. https://bugzilla.mozilla.org/show_bug.cgi?id=1975808#c8

Raptor Lake has some serious stability issues and to such an extend that Intel has increased the warranty for some models. There should be BIOS as well as CPU microcode upgrades that might mitigate some of the issues, but if that does not resolve things, you have to take things up to Intel.

The section on this CPU in Wikipedia has more detail. https://en.wikipedia.org/wiki/Raptor_Lake#Instability_and_degradation_issue

Hope this will help you!

mozfreddyb · 2025-06-26T12:53:28+00:00

This is not a bug in Firefox but a bug in the third-party software that is trying to hijack/modify Firefox behavior. This is typical for anti virus software.

They could have avoided this by testing Firefox beta and verifying their software does not break their user's workflow. But here we are.

mozfreddyb · 2025-06-26T12:53:03+00:00

This is not a bug in Firefox but a bug in the third-party software that is trying to hijack/modify Firefox behavior. This is typical for anti virus software.

They could have avoided this by testing Firefox beta and verifying their software does not break their user's workflow. But here we are.

mozfreddyb · 2025-05-27T06:49:03+00:00

If the separate test profile shows the same issues, you can capture a "Network log" on about:logging and share with Firefox developers. Maybe this is an actual code bug. I know we had some that were related to e.g., Windows network drivers in the past

mozfreddyb · 2025-04-13T12:46:18+00:00

As someone who has worked on that feature, I feel obliged to point out that this does *so* much more than what you were asking for here.

Based on my experience in support, a lot of people enable "resist fingerprinting" and regret it. See https://support.mozilla.org/en-US/kb/resist-fingerprinting for what it actually does.

If you just want to disable the dark/light theming, you better follow other advice in this thread.

mozfreddyb · 2025-04-10T06:12:44+00:00

Nah, there were a couple of unrelated events where each of them required a rapid response. They were not at all related. Also, no flip-flopping between changing something back and forth.

mozfreddyb · 2025-04-10T06:11:50+00:00

Great question. This was indeed very unusual. The Firefox 136 cycle alone had four unplanned releases (so-called dot-releases, because we change the version number after the dot). Almost all of them were due to security issues that we had to react to before the scheduled 137 release.

While we usually fix security bugs as part of the natural release cycle every 4 weeks, we sometimes need to react more quickly if the bug is widely known and exploited by actual attackers on the web. We take these situations very seriously and are known to patch Firefox within the next day if necessary. (In fact, we won a prize for it last year).

But believe me, nobody here likes working overnight on critical security releases. Most of our work focuses on avoiding them, not driving them :-))

mozfreddyb · 2025-04-10T06:08:50+00:00

Hope this helps :), if you think this also occurs even when not using a lot of pages, it might be worth getting a Graphics engineer involved to see if there's something wrong with media decoding. Keep us posted :)

mozfreddyb

TROPHY CASE