Last week, Mozilla released Firefox 136 with some new and interesting features. Now, a maintenance update to version 136.0.1 followed. ESR versions 128.8 and 115.21 are not affected. The update should be available later today via the update function in the browser.

Changes in this version 136.0.1

The update fixes an issue where a cookie size limit caused problems managing cookies on the website when using the CookieStore API. This could lead to login and other state-related issues. The update additionally fixes an issue where Ctrl/Command+L did not focus the address bar in new windows.

Read more in the official Release Notes.

Changes in Firefox 136

Below is an overview of the fixes and changes. A total of 15 security vulnerabilities were corrected last week. Of these, 8 were rated high. These include corrections that affect Thunderbird.

• Users can now enable the updated Firefox sidebar under Settings > General > Browser layout to quickly access multiple tools with one click without leaving your main view. Sidebar tools include an AI chatbot of your choice, bookmarks, history, and tabs from devices you sync with your Mozilla account.

• Got a lot of tabs open? Try our new vertical tabs layout to quickly browse your tab list. With vertical tabs, your open and pinned tabs are shown in the sidebar rather than at the top of the browser. To enable vertical tabs, right-click the toolbar at the top of the browser and select Turn on vertical tabs. Once you've enabled the updated sidebar, you can also go to Customize Sidebar and enable Vertical Tabs. Early testers report feeling more organized after a few days of using vertical tabs.

• The Clear browsing data and cookies dialog now allows users to delete saved data from forms separately from browsing history.

• Smartblock Embeds allows users to selectively unblock certain social media embeds that are blocked in Strict and Private Browsing ETP modes. Currently, support is limited to a few embed types, with more to be added in future updates.

• Firefox now updates page loading to HTTPS by default and automatically falls back to HTTP if the secure connection fails. This behavior is known as [HTTPS-First].

• On macOS, some background tabs are moved to low-power cores to reduce power consumption.

• Hardware-accelerated playback of HEVC video content is now supported on macOS.

• Hardware video decoding is now enabled for AMD GPUs on Linux.

• On Linux, Firefox is now available on ARM64 (AArch64), with installation options via APT and tarballs. Flatpak support coming soon.

• Address autofill has been enabled for users in the UK.

• For new tabs, the Save to Pocket action has been moved from a button to the context menu, along with other actions such as Bookmarks.

• The macOS DMG install packages now use LZMA for compression, reducing download size and installation time.

• Due to recent changes in macOS Sequoia, the keyboard shortcut for completing search strings to .com addresses has been changed from Ctrl+Enter to Cmd+Enter.

• Firefox now uses the PNG format when copying images out of Firefox, preserving transparency.