Firefox 153 contains itself while Thunderbird 153 fixes almost everything

Mozilla released Firefox 153 on Tuesday, closely followed by MZLA with Thunderbird 153 – codenamed "Meadow" for reasons that remain obscure for now. Firefox 153 is Mozilla's new Extended Support Release (ESR), so it will receive security updates until some time after the next ESR in mid-2027. We covered the highlights of what's new in this version last week.