Firefox Community Forum

Hi, In the last hour FF has stopped working completely. I made the mistake of using Ccleaner, which is probably the problem, I haven't had issues cleaning before, though I usually check the registry before deleting and don't recall seeing any entry for Mozilla (I may be wrong, though).

Firefox was working fine a couple of hours ago, but now it won't open at all, except in admin mode and then it won't open any links or tabs, not even settings. I've uninstalled FF, deleted the folder in the Programs folder, and reinstalled it from scratch, but there is no change (the one difference is that it wouldn't open in Admin after before I reinstalled it). Waterfox doesn't open either, but Thunderbird seems to work with no problems.

Thanks, Matt

• Firefox 127.0.2 (64 bit), Windows 10, all extensions disabled.
• Tested also with a clean portable version (same Firefox version).

In private mode, on Google Images, large images (in the preview pane: if you click on an image in the search results) are sometimes (but not always) blurry. This is not the case in the "normal", nonprivate mode.

It works fine on Android, and other browsers also work fine. I have had this issue for a very long time now, but only now realized that it's a private-mode issue.

Example, which is reproducible for me: Search "site:linkedin.com new york" on Google Images and pick an image with a sufficiently large resolution.

Ever since Facebook started infesting the chats with end-to-end encryption (random chats get "Messenger upgraded the security of this chat. Messages and calls are secured with end-to-end encryption" without my permission or asking if I want this), any encrypted chats have audio and video calls disabled. I note that I have ONE friend for whom it didn't do this, I can still do calls with her. If I receive a call, I get a pop-up saying that to receive this call I must download the Messenger app (no way) or a browser which supports it. If I check what browsers it thinks supports this, it only lists Chrome and Edge. As far as I know Edge is just Internet Explorer renamed, the biggest black hole in security, I've never touched it. Chrome ignores industry standards, so I don't use it. Making Firefox the best, top browser available. It's the only browser I wish to use. Mozilla needs to look into how to get Facebook to stop blacklisting Firefox like this. Note that this E2EE garbage has only been infecting things for the last few months, before that I was perfectly able to do any calls I wished in Facebook Messenger.

Hi, During some tests I found that FF 115.19.0esr can still execute arbitrary JS similarly to CVE-2024-4367. I’ve checked the versions and > 115.11esr should be patched. Any payload with ‘/JS’ taken from https://github.com/luigigubello/PayloadsAllThePDFs/tree/main will do. Since this is probably important – FontMatrix is *not* working (no JS), original PoC (https://codeanlabs.com/wp-content/uploads/2024/05/poc_generalized_CVE-2024-4367.pdf) is also *not* working. I also wasn’t able to call an external script and so far haven’t found any path to exploit it beyond an alertbox. However, it still bothers me a lot and I’d like to know whether it’s the correct, expected behavior with FF+pdf.js, is it a vulnerability, or maybe my browser was somehow corrupted or is using some other mechanism that’s not within your control (my settings? about:config?).

Steps to re-create: 1. Open file in notepad 2. Add ‘/OpenAction 99 0 R’ after ‘lang’ in ‘1 0 obj section’ 3. After ‘endobj’ add ‘99 0 obj <</Type /Action /S /JavaScript /JS (app.alert\(1\);)>>’ 4. Result – alertbox popping twice

I am using Firefox 128.5.0esr (64-bit) on Debian 12. This is the browser that comes installed with the system. Recently, an offline translation feature was added to Firefox. In settings, you can download various languages. I would like to know where language models for offline translation are stored. The downloaded languages I want to copy to another computer without internet connection so that I can use the offline translation on this computer.

In previous versions of Firefox (up to version 133), it was possible to automatically trigger printing of a PDF file by loading it into an iframe from a sandboxed iframe and call print. However, starting with version 134, this no longer works.

Is there any other way to automatically trigger the print dialog for a PDF file in Firefox, similar to how it can be done in Chrome/Edge (e.g., by opening the PDF in a new window and directly triggering the print dialog without additional button clicks)?

The font size in "Manage Bookmarks" is way too large, both in the sections list menu on the left and the list of bookmarks. I checked my userChrome.css file as well as the layout.css.devPixelsPerPx entry in about:config and there's nothing there to explain why only the "Manage Bookmarks" text is so large.

It's possible I changed a setting somewhere that's causing this. But I'm stumped re: what setting might be controlling the font size in only that UI. All other Firefox text sizes are good.

Thanks to anyone who knows where I should be looking

Firefox 134.0.1 (64-bit) Windows 10

Hi I created my own proxy that has the normal login screen but it also uses a 2fa feature which I cant get to work with firefox, I was wondering if you just do not have another pop up after the login screen or is my proxy the issue.

I SUBSCRIBE TO TOTAL AD BLOCK BUT I ONLY USE FIREFOX AND DO NOT SEE HOW TO DOWNLOAD THE APP.

PLEASE ADVISE THANK YOU DAVID VOSBEIN [edited phone# from community forum]

Why are my 3 rows of Home page tabs now so small? I can go to about:config, search for browser.newtabpage.activity-stream.newtabLayouts.variant-b and change to false and tabs are back to large. However, they soon revert back to very small. How can I keep them large?