
Firefox 140 released on June 26. But two issues crept in for some users, so the team created a patch version called Firefox 140.0.1. Firefox 140 ESR, 128.12 ESR, and 115.25.0 ESR are apparently not affected.
The issues that may occur include a startup crash that some users experienced due to a DLL injection, and issues with some Firefox dark themes and sidebar text contrast. Both bugs have been fixed.
Find the release notes here.