Firefox 159 fixes 167 security flaws, including 13 sandbox escapes

Source: PCWorld Security · OCT 28, 2026

Firefox 159 has been released for Windows, macOS, Linux, and Android. It comes with a new password tool in the sidebar, over 160 security vulnerability fixes, and an “AI”-assisted feature for monitoring websites for changes. Updates are also available for the Firefox ESR versions. The next major release, Firefox 160, is scheduled for November 10th. What’s new in Firefox 159? Passwords saved in Firefox are available in the sidebar without you first having to enable the password tool in the sidebar. In other words, the sidebar password app is enabled by default—even if you don’t save your passwords in Firefox at all. The AI-based Smart Window feature is designed to monitor websites for changes, such as new blog posts or price changes. This feature is being rolled out gradually, so it’s not yet available to all users. Security vulnerabilities fixed in Firefox 159 In the security advisory for Firefox 159 , Mozilla lists 167 security vulnerabilities that have been fixed. Of these, 65 were d