About this update
This update enables computers that have the out-of-date ActiveX control-blocking feature to consume a compressed version of the versionlist.xml file in Internet Explorer 11, Internet Explorer 10, Windows Internet Explorer 9, and Windows Internet Explorer 8.
To enable this update, install the most recent cumulative security update for Internet Explorer. To do this, go to Microsoft Update. Additionally, see the technical information about the most recent cumulative security update for Internet Explorer.
Note This update was first included in March cumulative security update for Internet Explorer (MS15-018).
Internet Explorer uses the versionlist.xml file to determine whether an ActiveX control should be stopped from loading. This file is updated with newly-discovered out-of-date ActiveX controls that Internet Explorer automatically downloads to your local copy of the file. Today, Microsoft delivers this file to clients uncompressed. This update is to enable computers to consume a compressed version of this file.
Note If you do not apply this update, your computer may be unable to download the versionlist.xml file in the future. Preventing this automatic download breaks the out-of-date ActiveX control blocking feature by not letting the version list update with newly outdated controls, potentially compromising the security of your computer. For more information, see Update to block out-of-date ActiveX controls in Internet Explorer.
See the terminology that Microsoft uses to describe software updates.