Except where noted, everything here applies only to Firefox 141 and the Firefox 140.1 ESR. Firefox 140 is the next ESR so, going forward, no enterprise changes will be backported to Firefox 128 ESR.

Bug Fixes

• The new sidebar was shown when using kiosk mode. This was fixed in bug 1948934.
• When support was added for extensions installed via policy to manage other extensions, extensions installed via the legacy Extensions policy were accidentally left out. This was fixed in bug 1972314.

Policies

• The Pocket policies in FirefoxHome have been restored for compatibility. We've added policies that use the word Stories instead of Pocket for future use. There are no plans to remove the Pocket policies.
• The Preferences policy has been updated to allow setting the preferences mathml.disabled, svg.context-properties.content.enabled, svg.disabled, webgl.disabled, webgl.force-enabled, xpinstall.enabled, and security.csp.reporting.enabled as well as prefs beginning with privacy.baselineFingerprintingProtection or privacy.fingerprintingProtection.

Special Notes

There is one more planned releases of Firefox 128 ESR, and then it will go out of support on September 16, 2025. Users will then be automatically upgraded to Firefox 140 ESR.

If you need to prevent upgrades for any reason, you can use the AppUpdatePin policy.