Mozilla sent Firefox Version 152.0.3 to the release channel.
From the Release Notes (https://www.firefox.com/en-US/firefox/152.0.3/releasenotes/?), the update includes a fix to an issue that could cause extreme memory usage and freezing on startup for users with language packs installed.
Update: To get the update now, select "Help" from the Firefox menu and pick "About Firefox". Mac users need to select "About Firefox" from the Firefox menu. If you do not use the English language version, Fully Localized Versions (https://www.mozilla.org/en-US/firefox/all/#product-desktop-release) are available for download.
Rapid Release Calendar (https://wiki.mozilla.org/Release_Management/Calendar)