Firefox 159 Released: Linux Improvements and New AI Features
Mozilla released Firefox 159 on its FTP server alongside corresponding maintenance updates Firefox 153.6 ESR and 115.44.0 ESR.
The staggered rollout follows Mozilla’s transition to a two-week release cycle implemented in September, which delivers features and bug fixes through smaller, more frequent updates rather than traditional four-week intervals.
Wayland Glitches and AMD Memory Fixes on Linux
For Linux users running Wayland, Firefox 159 resolves two prominent tab-handling glitches. Linux systems equipped with AMD graphics cards also receive a fix for excessive memory consumption triggered when rendering Mapbox GL JS-based maps. A bug was also fixed on Linux systems with AMD graphics where viewing maps based on Mapbox GL JS led to excessively high memory consumption.
Password Manager Moves to Sidebar
Interface adjustments relocate the built-in password manager to the sidebar by default. Users can now access a search function for open tabs using the keyboard shortcut [Ctrl]+[Shift]+[A]. Meanwhile, web developers gain support for CSS animations tied directly to scroll positions.
Smart Window Adds Price Drop Monitoring
Additional patches resolve issues with Chrome bookmark imports, the file selection dialog, and HTTP/2 page loading errors, alongside enhancements to Linux Vulkan support. Testers utilizing the AI-driven Smart Window feature can also deploy a new /watch command to monitor web pages for price drops or content updates.
Emergency Updates Patch Four Security Flaws
Accompanying the version 159 release, Mozilla deployed emergency maintenance updates designated as Firefox 158.0.1, Firefox 153.5.1 ESR, and Firefox 115.43.1 ESR to patch four distinct security flaws. According to DFN-CERT advisories cited by Linux-Magazin, the updates eliminate multiple vulnerabilities that could allow attackers to bypass security restrictions, gather information, execute arbitrary code, or launch denial-of-service attacks without user privileges. For the exploitation of the vulnerabilities, no privileges are required, and multiple vulnerabilities require user interaction.
OneCRL List Blocks Compromised Certificates
The maintenance packages incorporate an updated OneCRL revocation list to block compromised eMudhra intermediate certificates, ensuring clients reject the certificates even if remote settings are disabled by network policies or user configurations.
Further stability patches in Firefox 158.0.1 resolve a text-selection bug that caused web pages to scroll back to the top unexpectedly. Mozilla also corrected a Windows crash affecting users running screen readers or other assistive technologies while printing or saving a webpage as PDF, fixed a multi-monitor window placement bug on Linux, restored integration for built-in VPN activation, and resolved a macOS issue where files dragged from external applications failed to drop correctly.
Thunderbird 158.0.1 Updates
Mozilla also released an update to version 158.0.1 for Thunderbird on Windows, macOS, and Linux, alongside Thunderbird 153.5.1 ESR. The update fixed problems where dialogs had transparent backgrounds when using third-party themes. Mozilla Thunderbird is a free email client and personal information manager featuring CalDAV support, a feed reader, newsreader, and messaging and chat client, and is one of the most widely used email programs alongside Microsoft Outlook and proprietary operating system pendants.
Official Rollout Slated for November
Mozilla has scheduled the official rollout for Firefox 160 on November 10.