Mozilla extends Firefox ESR 115 support for legacy OS users until March 2026

Mozilla has confirmed that support for Firefox Extended Support Release (ESR) 115 on older platforms, including Windows 7, 8.1, and macOS 10.12–10.14, will now continue through March 2026.

The announcement notification notes that the decision will be reevaluated in early 2026, with any further updates to the end-of-life timeline revealed in February.

For the uninitiated, this is the third extension of support for these legacy systems. Initially, support had been set to expire in March 2025, but Mozilla pushed that date first to September 2025, and again to March 2026.

Mozilla’s continued backing contrasts with other browser vendors like Google and Microsoft, who have already dropped support for these older operating systems. This extension allows users on unsupported platforms to keep receiving critical security updates for as long as possible.

By offering additional blocks on immediate end-of-life, Mozilla is looking to minimize risk for users who still rely on older systems. For now, users can run Firefox ESR 115 safely, without losing access to essential security patches, until at least March 2026.