Firefox Tomorrow
Stable 140.3.1

Firefox ESR 140.3.1

Tuesday, September 23, 2025 3 changes 2 categories
Fixed (1) Developer (2)

TL;DR

1 fix, 2 other changes. Highlight: Improved reliability when HTTP/3 connections fail: Firefox no longer forces HTTP/2 during fallback, allowing the server to choose the pro…

Fixed 1 item
  1. 01

    Improved reliability when HTTP/3 connections fail: Firefox no longer forces HTTP/2 during fallback, allowing the server to choose the protocol and preventing stalls on some sites. ( Bug 1980812 )

Developer 2 items
  1. 01

    Developer Information

  2. 02

    Reference link to ESR 140.3.0 release notes .