Firefox Browser, also known as Mozilla Firefox or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards. In 2017, Firefox began incorporating new technology under the code name Quantum to promote parallelism and a more intuitive user interface. Firefox is officially available for Windows 7 or newer, macOS, and Linux. Its unofficial ports are available for various Unix and Unix-like operating systems including FreeBSD, OpenBSD, NetBSD, illumos, and Solaris Unix.
What's new in 158.0.1
Version 158.0.1, first offered to Release channel users on October 20, 2026
Fixed
Mozilla blocked compromised eMudhra intermediate certificates via OneCRL on October 17th. The blocks were distributed to clients via Remote Settings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is disabled by policy or otherwise unavailable in the user's network environment. (Learn More)
Fixed an issue where pages would unexpectedly scroll back to the top when selecting text. (Bug 2081016)
Fixed a crash on Windows when printing or saving a page as PDF while a screen reader or other assistive technology was running. (Bug 2082376)
Fixed an issue where Firefox was opening windows on the wrong monitor in multi-monitor setups on Linux. (Bug 2076558)
Fixed an issue that could prevent the built-in VPN from turning on for some users. (Bug 2055094)
Fixed an issue where files dragged into Firefox from other applications were not dropped onto the page on macOS. (Bug 2078954)
