Firefox ESR 115.39, ESR 140.14, and ESR 153.1 released

[Dianna Smith]

We are pleased to announce that the Firefox ESR 140.14 release is now available for download at https://www.firefox.com/download/all/desktop-esr/.

Release notes for Firefox 140.14.0esr are available at
https://www.firefox.com/firefox/140.14.0/releasenotes/
Associated security advisories are posted at:
https://www.mozilla.org/security/advisories/mfsa2026-76/

Firefox ESR 115.39.0 is also now available for Windows 7-8.1 and macOS 10.12-10.14 users.

Release notes for Firefox 115.39.0esr are available at
https://www.firefox.com/firefox/115.39.0/releasenotes/
Associated security advisories are posted at:
https://www.mozilla.org/security/advisories/mfsa2026-75/

Firefox ESR 153.1.0 is the second release from the ESR153 branch, which is slated to replace ESR140 on October 13, 2026.
We recommend that organizations use this opportunity to test the new major release in their environment and provide any feedback ahead of the ESR153 end of life.

Release notes for Firefox 153.1.0esr are available at 

https://www.firefox.com/firefox/153.1.0/releasenotes/

Associated security advisories are posted at:
https://www.mozilla.org/security/advisories/mfsa2026-77/

As always, we recommend that users keep up to date with the newest version of Firefox ESR for the latest stability and security fixes.

Thank you,

Dianna Smith
Firefox Release Manager