Firefox has been significantly enhanced with the release of version 146, bringing a suite of improvements focused on data security and user control. This update addresses critical vulnerabilities and introduces features designed to streamline the user experience, particularly for those transitioning between Windows versions.
A key addition is a new backup feature for Windows users, offering a seamless way to transfer essential browser data when upgrading from Windows 10 to Windows 11. This local or OneDrive-based backup eliminates the need for account synchronization, prioritizing user privacy and convenience.
Privacy-conscious users will appreciate the refined location access controls, especially within the European Union. Firefox now requires explicit consent before determining a user’s location for features like the homepage weather report, reinforcing a commitment to data protection.
Experimentation within Firefox is now more accessible. Users can explore cutting-edge features through Firefox Labs without being required to share telemetry data, fostering innovation while respecting user preferences.
Under the hood, Firefox 146 delivers substantial security improvements. Mozilla has resolved at least thirteen identified vulnerabilities, five of which are classified as high risk. These include critical fixes for errors within the JavaScript JIT compiler and a use-after-free vulnerability in the WebRTC component.
Two internally discovered flaws, while considered medium risk, have also been addressed. Though currently unexploited, these vulnerabilities were proactively patched to maintain a robust security posture. The details are documented in the 2025-92 Security Advisory.
Beyond the standard release, updated Extended Support Release (ESR) versions – 140.6.0 and 115.31.0 – are available. These updates provide vital security patches for older systems, including Windows 7, 8.1, and macOS versions 10.12 to 10.14.
The Tor Browser has also received updates, with version 15.0.3 based on Firefox ESR 140.6 and including the NoScript 13.5.2 extension. A separate version, 13.5.26, is available for older operating systems, built on Firefox ESR 115.31.
Complementing the browser updates, Thunderbird, the popular email client, has been updated to versions 146.0 and 140.6.0esr. These releases inherit the security enhancements from Firefox, ensuring a secure and reliable email experience, including improved Exchange support.
Mozilla plans to release Firefox 147 on January 13th, 2026, aligning with Microsoft’s Patch Tuesday schedule, demonstrating a continued commitment to timely security updates and a proactive approach to safeguarding user data.
