Does Firefox Automatically Update ESR?
Does Mozilla provide an upgrade path between two ESR versions? Yes, an ESR will be automatically upgraded to the subsequent ESR. System administrators can disable automatic updates by managing ESR through their deployment system.
How often does Firefox ESR update?
Extended Support Release (ESR): receives major updates on average every 42 weeks with minor updates such as crash fixes, security fixes and policy updates as needed, but at least every four weeks.
Choosing a Firefox update channel - Mozilla Support
Is Firefox ESR no longer supported?
Firefox ESR versions are maintained for a longer period compared to stable releases. ... The latter will see two additional releases, Firefox 78.14 ESR and Firefox 78.15 ESR before it will be discontinued; this will happen in October 2021. Firefox 91 ESR marks the beginning of a new base for extended support releases.
Firefox ESR 91: new ESR version will be released tomorrow - gHacks
What is latest Firefox ESR version?
Firefox ESR 91.0esr, See All New Features, Updates and Fixes.
Firefox ESR Release Notes - Mozilla