March 2021 CU for SharePoint Server 2016 is available for download

The product group released the March 2021 Cumulative Update for SharePoint Server 2016 product family.

This CU also includes Feature Pack 1 which was released with December 2016 CU and Feature Pack 2 which was released with September 2017 CU.

The KB articles for March 2021 CU are available here:

  • KB 4493232 – March 2021 Update for SharePoint Server 2016 (language independent) – This is also a security update!
  • KB 4493199 – March 2021 Update for SharePoint Server 2016 (language dependent) – This is also a security update!

The download for March 2021 CU is available here:

Important: It is required to install both fixes (language dependent and independent) to fully patch a SharePoint server. This applies also to servers which do not have language packs installed. The reason is that each SharePoint installation includes a language dependent component together with a language independent component. If additional language packs are added later (only) the language dependent fix has to be applied again.

It is irrelevant which language you pick on the drop down in download center. Even the language dependent fixes are all in the same package for all languages.

After installing the fixes you need to run the SharePoint 2016 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.

SharePoint 2016 March 2021 CU Build Numbers:

Language independent fix: 16.0.5134.1001
Language dependent fix: 16.0.5134.1000

To understand the different version numbers please have a look at my article which explains the different SharePoint build numbers.

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

Related Links:


  1. Hi Stefan, does this CU include updates which released with past CUs for SP 2016?


    1. Yes – otherwise it would not be a CU.


  2. Any known issue in this patch since i am going to patch the PROD servers. Please let me know if any


    1. Hi Tina, have you applied the patch in PROD in the meantime? What are your experiences so far?


  3. Have you applied the patch in PROD in the meantime? What are your experiences so far?


  4. can we dismount/mount all content databases during in sharepoint server 2016 pre-post CU installation. is it fine to perform the step and what will be the criticality if we do so ?


    1. Hi Nischay,
      you can certainly do this but I’m not sure what the benefit would be as it would cause a downtime which can be avoided otherwise using zero-downtime patching functionality.


  5. Hi Stephen,

    We are planning to Install March 2021 CU in our SharePoint 2016 servers and we also want to patch for this vulnerability.

    Can you please let us know if the fix for this vulnerability is included in March 2021 CU or do we need to install separate hot fix.
    If its not included then how to install both together March 2021 CU+ Host fix.


    1. Hi Subhash,
      this is fixed in June 2021 CU.
      So rather than installing March CU you would need to install June CU.


          1. Hi Stephen,

            So in order to install the hot fix for this Vulnerability then we need to install KB 5001946 & KB 5001922 which also include previous update as well and then our farm version will change to June 2021.

            Is it possible to install only security update for this fix and not complete June 2021 CU.

          2. Hi Subhash,
            SharePoint fixes are cumulative and always include all security and non-security fixes up to this point.

  6. Hello Stefan,

    Is there an order to install the Language independent and the Language dependent fixes or it doesn’t matter?

    The configuration wizard is only executed after installing both fixes correct?



    1. Hi Rui,
      there is no reqired sequence.
      PSConfig is only required once.


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