Disabling legacy scripting engine JScript in Internet Explorer
Published Oct 13 2020 03:32 PM 12.7K Views
Microsoft

To help you provide a more secure browsing experience across your organization, the October 2020 monthly security updates for Windows and Windows Server introduce an option to block Jscript (Jscript.dll) execution in Internet Explorer 11.

Jscript is a legacy Microsoft implementation of the ECMA 262 language specification. Blocking Jscript helps protect against malicious actors targeting the JScript scripting engine while maintaining user productivity as core services continue to function as usual.

Recommended actions

As a security best practice, we recommend that users disable the legacy JScript execution for websites in the Internet and Restricted Sites zones. Details on how to configure this behavior can be found in the following article: Option to disable JScript execution in Internet Explorer (KB4586060).

Microsoft will continue to provide security updates for JScript via the latest cumulative updates for Windows 10, and Cumulative Updates for Internet Explorer 11 or Monthly Rollups for Windows 8.1, Windows Server 2012, and Windows Embedded 8 Standard. If you have
automatic updates enabled, updates will be automatically downloaded and installed on your users' devices. If you have disabled automatic updates for your organization, you will need to check for updates and install them manually.

2 Comments
Copper Contributor

The knowledge base says that older devices must be configured with a feature control key, but nowhere does it say the name of the registry to set.

And there's something wrong with the registry name you set in the WOW6432Node.

Bronze Contributor

This is great decision and script are source of several malicious activities in system and this would block several known and unknown attacks.

Version history
Last update:
‎Oct 13 2020 03:32 PM
Updated by: