Quote:

Microsoft released an out-of-band emergency security update for Internet Explorer on September 23, 2019 for all supported versions of Windows.

The emergency update is only available on the Microsoft Update Catalog website at the time of writing and not through Windows Update or WSUS.

Some support articles provide little information. The Windows 10 update description simply states "
Updates to improve security when using Internet Explorer" without going into further detail. The page links to the Security Update Guide which, after some digging, leads to the CVE of the vulnerability.

The support page for the cumulative update for Internet Explorer offers more information and a direct link to the CVE.

It states:

Quote:This security update resolves a vulnerability in Internet Explorer. A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could run arbitrary code in the context of the current user. The security update addresses the vulnerability by changing how the scripting engine handles objects in memory.

...