March 2021 CU for SharePoint 2010 product family is available for download

The product group released the March 2021 Cumulative Update for the SharePoint 2010 product family.

For March 2021 CU we have full server packages (also known as Uber packages) for Server and Project Server. The latest available full server package for SharePoint Foundation was released with February 2021 CU.

As this is a common question: Yes, March 2021 CU includes all SharePoint security fixes released with March 2021 PU.

Be aware that CU is a Post-SP2 hotfix. It is required to have SP2 installed before installing the CU.
It is required to have SP2 installed for the base product and all installed language packs to install March 2021 CU for SharePoint 2010.

This CU includes all SharePoint 2010 fixes (including all SharePoint 2010 security fixes) released since SP2. The CU does not include SP2.

The KB articles for March 2021 CU should be available at the following locations in a couple of hours:

  • There was no fix released for SharePoint Foundation 2010 with March 2021 CU
  • KB 4504706 – SharePoint Server 2010 March 2021 CU
  • KB 4504704 – Project Server 2010 March 2021 CU

The Full Server Packages for March 2021 CU are already available through the following links:

After installing the fixes you need to run the SharePoint 2010 Products Configuration Wizard on each machine in the farm. If you prefer to run the command line version psconfig.exe ensure to have a look here for the correct options.

Be aware that the SharePoint Server 2010 CU contains the SharePoint Foundation CU.
That means only one package has to be installed for the SharePoint 2010 product family.

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

Related Links:


  1. Hi,
    Since application of CU March patch on our SP 2010 farm, one InfoPath solution is corrupted. Any usage of magnifying glass generates an error:
    Exception occurred during request processing. (User: ###, Form Name: , IP: , Request: http://###/_layouts/FormServer.aspx?XsnLocation=http://###/FormServerTemplates/Form.xsn&SaveLocation=http://###/prePR&Source=http://###&DefaultItemOpen=1, Form ID: , Type: BlockedTypeException, Exception Message: SafeSerialization[Context=EnhancedBinaryReader Deserialization]: type System.Collections.Generic.List`1[[System.String, mscorlib, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089]] not allowed.)
    Source: InfoPath Forms Services
    Is it possible that this file is the reason:
    Best regards.


    1. This not been reported before. If you need assistance, please open a ticket with Microsoft support.

      But please keep in mind that this product version will go out of support in a couple of days.


      1. Hi,
        This is the reason why I’m very upset because this is one of the last CU to install.
        Best regards


        1. Hi Loïc,
          in general we recommend to stop using SharePoint 2010 after end of the support date because new discovered security issues including zero day exploits will not be fixed.
          Using the product after end of support will potentially put business data and your environment at risk.
          It is very important to upgrade to a newer version of the product asap.


  2. I have same Loïc error on Infopath. Can you help me?


  3. Did you guys experienced issues creating new sites after applying the update?


  4. Hi,
    The issue is related to a developed Infopath from with code behind.
    Solution applied was to replace the Microsoft.Office.InfoPath.Server.dll (version 14.0.7267.5000, CU March 2021) by an old one (14.0.7011.1000 CU February).
    The goal was to set this very useful InfoPath form in production.
    Best regards.


    1. Hi Loïc,
      be aware that
      – the approach you used is unsupported
      – you removed parts of the security fixes included in March CU using this method

      You should really open a ticket with Microsoft to get this analyzed.


    2. Hi Loic, how can I get the February 2021 DLL? We updated one SP2010 server using InfoPath Forms last weekend and are now getting same issues. We need to find a solution asap as our users are not able to work. Microsoft Ticket was opened, but we need a workaround so that our users are able to work again.



      1. Hi,
        I can share you this file.
        Let me know how we can proceed.


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