I think it’ll be 52 through 60 inclusive.
Postscript
For clarity (from a recently added point at Add-ons disabled or failing to install in Firefox | Mozilla Add-ons Blog), with added emphasis:
… For users who cannot update to the latest version of Firefox or Firefox ESR, we plan to distribute an update that automatically applies the fix to versions 52 through 60.
Edge cases that will benefit from an automated fix may include:
- users who are ‘stuck’ on Firefox ESR 60.6.1 and can not (or will not) enable studies.
This fix will also be available as a user-installable extension. …
Users of Waterfox 56.2.9 may either:
- await promotion of the extension by Mozilla; or
- await an update to the application from Waterfox Project.