Mozilla released Firefox 85.0.1 Stable and Firefox ESR 78.7.1 to the public on February 5, 2021. The new browser versions are already available and will be installed automatically on most systems thanks to the build-in updating functionality of the browsers.
Standalone downloads are provided on the Mozilla website. Select Menu > Help > About Firefox to display the currently installed version of the browser.
Firefox 85, the last major release of the browser, was released on January 26, 2021.
Firefox 85.0.1 release information
Firefox 85.0.1 and Firefox ESR 78.7.1 are security updates first and foremost. Mozilla patched a single security issue in both versions of the browser.
The vulnerability, Buffer overflow in depth pitch calculations for compressed textures, has received the severity rating critical, the highest rating available. Mozilla notes that the issue affects Firefox running on Windows machines only, all other supported operating systems are not affected by the issue.
Firefox 85.0.1 fixes five non-security related bugs in the browser next to that.
Two address crashes of the browser: the first when authenticating to websites using SPNEGO on macOS devices with Apple Silicon CPUs, the second in case of an unexpected Cache API state.
Linux users who tried to launch Flatpack or rpm Zoom client from Flatpack in Firefox 85 noticed that they could not do so anymore. The third fix of the new release addresses that issue by fixing external URL scheme handlers when using the Firefox Flatpack.
Mozilla engineers implemented a change in Firefox 85.0.1 that prevents access to NTFS special paths when using the browser; Mozilla notes that the access could lead to filesystem corruption.
The final fix prevents Firefox from printing an extra sheet of paper at the end of certain documents. The bug reporter on [email protected] experienced the issue when printing PDF documents with the setting layout.display-list.improve-fragmentation set to enabled.
You find the official release notes here.
Firefox 85.0.1 fixes several issues that affect specific operating systems only. The security fix affects Windows, one of the crashes only Mac devices with Apple Silicon processors, and the external URL scheme handlers only Linux systems