Mozilla warns users to update Firefox before certificate expires

Mozilla warns that a root certificate used to sign Firefox add-ons will expire on March 14, 2025, and advises users to update to Firefox 128 or later (or ESR 115.13+) to avoid add-on failures and degraded security protections. The issue affects Firefox on Windows, Android, Linux, and macOS (not iOS), and users of Firefox-based browsers should ensure their versions are based on Firefox 128+. Users can verify and trigger updates via Menu → Help → About Firefox, and Mozilla has provided support resources for those encountering update issues.