Google announced Chrome 66 to the stable channel for Windows, Mac, Linux, and users started upgrading to the new a version of Chrome 66.0.3359.117 that comes with a number of security fix and improvements.
Chrome 66 Targets Security
Strict site isolation which allows each website to have a dedicated process isolated from other sites, it was introduced in version 63 but not enabled by default.
In the address bar at the top, enter chrome://flags/#enable-site-per-process and press Enter.
Next to “Strict site isolation,” click Enable.
If you don’t see “Strict site isolation,” update Chrome.
Click Relaunch now.
The massive change is with the certificate that was issued by Symantec before June 1, 2016, those will stop function with Chrome 66 and from Chrome 70 all remaining Symantec SSL/TLS certificates will stop working. Chrome 70 set to be released on Aug 30th, 2018.
The release includes the fix for 62 security bugs that reported by the security researchers and Google says “bug details and links may be kept restricted until a majority of users are updated with a fix”.
You can find the complete list of changelog here and here for Security Fixes. It includes a number of fixes such as SmartScreen bypass in the download, URL spoof in Navigation, Fullscreen UI spoof and Confusing autofill settings.
From Chrome 66 it begins alerting users if any third party software tries to inject any code in Chrome and asks users to remove the software.
Starting from Chrome 68 which set to release by July 2018 it begins to block the third-party software from injecting into chrome and starting from Chrome 72 this option will be removed and it always block code injection.
Also, they announced safe browsing by default in the WebView starting this April 2018 from the WebView version 66. This means Android app developers using WebView not required to make any protection.