August 2021 CU for SharePoint Server 2016 is available for download

The product group released the August 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 August 2021 CU are available here:

  • KB 5002002 – August 2021 Update for SharePoint Server 2016 (language independent) – This is also a security update!
  • There was no language dependent fix released this month. The most recent language dependent fix is KB 5001981 from July 2021 CU

The download for August 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 August 2021 CU Build Numbers:

Language independent fix: 16.0.5200.1000
Language dependent fix: N/A

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:

11 Comments


  1. Does this CU fixed the issue of 2010 Workflow of July CU? Please let me know. We have installed March 2021 CU’s on servers. Can I now install August CU’s as this update replaces previously released security updates. Please suggest.

    Reply

    1. Hi Anu,
      there seems to be a misunderstanding: there is no problem in July CU. The changed behavior for SP2010 workflows was introduced by a security fix.
      The new behavior is expected. Out of the box SP2010 workflow should not have any issue and any custom written workflow actions will need to be implemented following the guidance in KB 5004862
      https://support.microsoft.com/en-us/topic/some-scenarios-of-sharepoint-2010-workflow-are-affected-after-applying-the-july-security-update-for-sharepoint-server-kb5004862-be361cd6-9f54-48c4-b890-2c4b7cf49d13:

      “If the blocked parts are written by using custom code, and you deploy them yourself in SharePoint Server, you should do a security review on the type that you’re trying to use. If that type is determined to be safe, you can add it to the web.config’s list of authorized types. Otherwise, you should create an alternative implementation that does not violate the security validations.”

      Cheers,
      Stefan

      Reply

  2. Hi Stefan,
    you say that Nintex should not have used the int64 type from mscorlib?
    As these lines are needed now in every web.config?
    Who else than Microsoft should be able to say if this is safe or not?

    Forgive me, if I am missing something.

    Thanks
    Christoph

    Reply

    1. Hi Christoph,

      mscorlib contains a large number of types. Other libraries in .NET even more.
      Not all of them are save. Microsoft marked those as save which are tested and used in out of the box workflow activities. Developer of custom activities might use additional types and they need to evaluate if these are save or if the workflow activities need to be adjusted to be save. If they are save the developer of the custom acitivities should either provide guidance to enable the activities or even better release an updated installer or patch which adds the required changes to the web.config using SPWebConfigModification class.

      Nintex released the relevant guidance for the custom activities they created and from the article it seems they are working on a fix to ensure that either the modificaitons are no longer required or automatically added to the web.config: “We will provide an update once the resolution has been included in an updated build of Nintex Workflow for SharePoint On Premises.”

      Cheers,
      Stefan

      Reply

      1. Hi Stefan,
        thanks. Yes, Nintex released a new version that does the web.config entries automatically (while the guidance article has not been updated yet).
        Regards
        Christoph

        Reply

        1. Hi Christoph,
          thanks a lot for the information! 🙂
          Cheers,
          Stefan

          Reply

  3. Good morning,
    Was there not an update for the Office Online server for the month of August?

    Krista

    Reply

    1. Hi Krista, there was no OOS fix released in August.

      Reply

  4. Good morning,
    I have the July update installed.
    When installing the August update, should I re-roll the July KB 5001981 (language dependent fix) after installing KB 5002002 (language independent)?

    Oleg

    Reply

    1. Hi Oleg,
      if 5001981 was already installed it is neither necessary nor possible to install it again.
      Cheers,
      Stefan

      Reply

  5. Anyone see any problems with the Microsoft Service Fabric Host Service after this patch?

    Reply

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