MS WIN98SE Update -no KB*** number?

I still check Windows Update even though I know they don't support WIN98SE anymore.
Today I get a Critical Update without the usual KB*** number (see below, note the date).
We had done some finagaling with the computers in the last week trying to get the home network set up. Yes, one of the PCs is WINXP.
Should I trust this site/update and go ahead with it?
I figure us fooling with the network triggered it, but I would like a second opinion before trusting this unusual update.
As usual, THANKS!

Security Update, December 17, 2001

This update resolves the Unchecked Buffer in Universal Plug and Play Can Lead to System Compromise security vulnerability in Windows 98 and Windows 98 Second Edition with Windows XP Internet Connection Sharing Client installed. Download now to help prevent a malicious user from compromising your computer or using your computer to compromise another computers functionality.
Note This update replaces Security Update, October 29, 2001, which is discussed in Microsoft Security Bulletin MS01-054. (This site is in English.)
For more information about this issue, read the Microsoft Security Bulletin on the Microsoft Security Web site. (This site is in English.)
System Requirements
This update applies to the following operating systems:
 Windows 98.
 Windows 98 Second Edition (SE).
Note If you are running Windows 98 or Windows 98 Second Edition, your computer is vulnerable only if the Windows XP Internet Connection Sharing Client has been installed from the Windows XP CD.
How to use

(This is the URL shown)
http://v4.windowsupdate.microsoft.com/en/default.asp