Try downloading Firefox from Mozilla. Download, unzip, and run firefox-bin from the folder and see if you have the same issue. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release X11 or Wayland? I assume you already tried running your distro version in Safe Mode?

This doesn't look to me like a distro version.

You can try to disable http3 via about:config.

• about:config => network.http.http3.enable => false

This doesn't look to me like a distro version. You can try to disable http3 via about:config.

• about:config => network.http.http3.enable => false

this seems to fix the issue, thanks!

This doesn't look to me like a distro version. You can try to disable http3 via about:config.

• about:config => network.http.http3.enable => false

Wondering how to let the developer team know this and fix this issue properly? I want to use those HTTP/3 features :( (though a browser that is not crashing but does not support HTTP/3 is better than a unusable crashing one)

Does it still happen with the flatpak version?

There are quite a few http3 prefs and I don't know if disabling one or more of the other http3 prefs instead of fully disabling http3 would stop the crashes.

There is a bug linked to the crash report and a GitHub link:

• 1829989NEW --- Crash in [@ neqo_transport::connection::Connection::build_packet_header]
• https://github.com/mozilla/neqo/issues/1429