The Firefox 91 web browser has been released. Firefox 91 is categorized as a long-term support (ESR) branch, with updates released throughout the year. In addition, an update of the previous branch with a long support period 78.13.0 has been formed (two more updates 78.14 and 78.15 are expected in the future). The Firefox 92 branch, which is scheduled for release on September 7, will soon be transferred to the beta testing stage.
Main innovations:
- In private browsing mode, the HTTPS-First policy is enabled by default, similar to the "HTTPS Only" option previously available in the settings. When you try to open a page without encryption via HTTP in private mode, the browser will first try to access the site via HTTPS ("http://" is replaced by "https://"), and if the attempt fails, it will automatically access the site without encryption. An important difference from HTTPS Only mode is that HTTPS-First does not apply to downloading sub-resources such as images, scripts, and style sheets, but only when you try to open a site after clicking on a link or typing a URL in the address bar.
- The mode of printing a reduced version of the page is returned, resembling the view in Reader Mode, in which only the significant text of the page is displayed, and all related controls, banners, menus, navigation bars and other parts of the page that are not related to content are hidden. The mode is enabled by activating the Reader View before printing. Support for this mode was deprecated in the Firefox 81 release, after switching to a new preview interface before printing.
- The capabilities of the Total Cookie Protection method, which is activated in private browsing mode and when the strict mode of blocking unwanted content (strict) is selected, have been expanded. The mode implies the use of a separate isolated storage for Cookies for each site, which does not allow using Cookies to track movement between sites, since all Cookies set from third-party blocks loaded on the site are tied to the main site and are not transmitted when accessing these blocks from other sites. In the new version, to prevent hidden data leaks, the Cookie () clearing logic has been changed and users have been informed about sites that save information locally.
- Changed the logic of saving files opened after loading. Files opened after downloading in external applications are now saved in the regular "Downloads" directory, instead of the temporary directory. Recall that Firefox offers two download modes - download with saving and download with opening in the application. In the second case, the downloaded file was stored in a temporary directory, which was deleted after the session ended. This behavior caused dissatisfaction among users who, if they needed direct access to the file, had to additionally look for the temporary directory in which the file was saved, or re-upload the data if the file had already been automatically deleted.
- Catch-up paints optimization is enabled for almost all user actions, which made it possible to increase the responsiveness of most operations in the interface by 10-20%.
- Support for single sign-on (SSO) technology has been added to builds for the Windows platform, which allows you to connect to sites using credentials from Windows 10.
- In builds for macOS, the high contrast mode is automatically enabled when the βIncrease Contrastβ option is activated in the system.
- "Switch to Tab" mode, which allows you to switch to a tab from the list of recommendations in the address bar, now also covers pages in private browsing mode.
- The Gamepad API is now only available when the page is opened in a Secure Context, i.e. when opened via HTTPS, via localhost or from a local file;
- The desktop version supports the Visual Viewport API through which you can determine the actual visible area, taking into account the display of the on-screen keyboard or scaling.
- Added methods: Intl.DateTimeFormat.prototype.formatRange() - returns a localized and formatted string with a date range (for example, "1/05/21 - 1/10/21"); Intl.DateTimeFormat.prototype.formatRangeToParts() - Returns an array with locale-specific parts of a date range.
- Added Window.clientInformation property similar to Window.navigator.
In addition to innovations and bug fixes, Firefox 91 fixes 19 vulnerabilities, of which 16 are marked as dangerous. 10 vulnerabilities (collected under CVE-2021-29990 and CVE-2021-29989) are caused by memory problems such as buffer overflows and access to already freed memory areas. These issues can potentially lead to malicious code being executed when specially designed pages are opened.
Source: opennet.ru