Mozilla has released a critical update for Firefox that repairs a security flaw that could have allowed hackers to run unauthorized code on a user's PC.
The new release, fixes an issue with the browser's interface code, part of which wasn't properly sandboxed. This provided a possible point of access for malicious code to run on the host computer.
The vulnerability has been present in Firefox since version 56, which was released in September last year. There are no examples of it being exploited in the wild, but the potential threat led Mozilla to release a fix immediately.
The update is available to download manually, but the browser will update automatically unless you've deliberately disabled the option.
The issue was discovered by Mozilla engineer Johann Hoffman, and involves the browser's 'chrome' component. This is nothing to do with Google Chrome, but instead refers to parts of a program's interface, including menus, toolbars and title bars, that are separate from the content being displayed.
In Firefox's case, these elements weren't fully isolated from the webpage code, providing a potential vector for malware.
The flaw is only present in the desktop browser; Firefox for Android is unaffected.