Provided a stable platform for IT administrators to test transition to the newer Firefox 102 ESR branch.

Available in 32-bit (win32) and 64-bit (win64) versions. macOS: Found in the mac directory. Linux: Available for i686 and x86_64 architectures.

Addressed high-impact vulnerabilities, including memory safety bugs (CVE-2022-38478) and address bar spoofing issues (CVE-2022-38472).

Firefox 91.13 ESR (Extended Support Release) is a specific build designed for organizations and users who prioritize stability and security over frequent feature updates. Released on , it served as the final planned maintenance update for the version 91 branch before it reached its end-of-life. Where to Download Firefox 91.13 ESR

Because version 91.13 is no longer the current supported ESR version, it is typically accessed through Mozilla’s official FTP archives .

As a maintenance update, version 91.13 focused on stability and security rather than new UI elements: