SharePoint security fixes released with September 2021 PU and offered through Microsoft Update

Below are the security fixes for the SharePoint OnPrem versions released this month.

SharePoint Foundation security fixes also have to be applied on SharePoint Server installations.
SharePoint Server security fixes also have to be applied on Project Server installations.

SharePoint 2013 Suite:

SharePoint 2016 Suite:

SharePoint 2019 Suite:

Office Online Server:

  • KB 5001999 – Office Online Server
See the Security Update Guide below for more details about the relevant fixes:

More information:

Please ensure to have a look at the SharePoint Patching Best Practices before applying new fixes.

1 Comment

  1. Hello,

    Thanks for your informations about updates. I successfully installed these last updates and ran configuration wizard well without errors. I’m on SharePoint server 2019. Everything is running fine, except a few little problems on modern sites themes :

    The top bar has lost the theme’s color and is now black, except for the apps button
    The left navigation menu elements don’t have the background color when mouse is hover anymore

    On classic experience, this doesn’t happen and changing theme of the site doesn’t help

    It’s not a big deal, but I wonder why I have these kind of problems and how to solve it… If you have an idea?



Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.