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

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

Important:
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:

  • KB 5001935 – SharePoint Server 2013 (core component)
  • KB 5001928 – Office Web Apps Server 2013

SharePoint 2016 Suite:

  • KB 5001917 – SharePoint Server 2016 (language independent)

SharePoint 2019 Suite:

  • KB 5001916 – SharePoint Server 2019 (language independent)

Office Online Server:

  • KB 5001914 – 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.
 

14 Comments


  1. Hey there,

    Should KB 5001915 be included in the SP 2019 bulleted list?

    Thanks!

    Reply

    1. Hi GB,
      no it should not be included.
      This blog post lists only the security fixes. 5001915 is not a security fix.
      Cheers,
      Stefan

      Reply

  2. We have applied KB5001933 and performed SharePoint upgrade. Do we still nee to apply KB5001935 on top of what we already have applied?

    Reply

    1. Hi JK, no that is not required. The CU of a given month contains all security fixes of the same and earlier months.

      Reply

  3. Hello Stefan,
    shouldn’t be there a KB5001926 for Sharepoint Server 2013.

    Reply

    1. Hi Sebastian,

      5001926 is not a security fix. This page lists the security fixes for SharePoint.

      Cheers,
      Stefan

      Reply

      1. That is right, thank you for claryfication.
        Regards,
        Sebastian

        Reply

  4. Hi
    Do anyone have problems with X-FRAME-OPTIONS after applying KB5001916 and KB5001917?

    “We have browser compatibility issues with Add an app page post the security patch deployment. This is the reason for the site creation issue also. The X-Frame options is set to DENY only when we browse to add an app page.”

    “The network error indicate that X-FRAME-OPTIONS has conflict values when open the dialog.”

    BR
    Boyan K.

    Reply

    1. I received information that this problem also exists in SharePoint 2013 after KB5001935

      Reply

    2. Did you find any fix for that and what caused this?

      Reply

    3. I also ran into the same error when “adding an App”, the permissions pop-up does not load and shows the X-FRAME-OPTIONS conflict Deny error. Dont have these specific KB’s but I installed all the available security patches on the Sharepoint 2019 server. For now working around it by using “Internet Explorer”, mysteriously there is no conflict on that browser and am able to add the App.

      Reply

      1. Hi Sarva,
        thats correct – Internet Explorer is the only browser which was not affected by this issue.
        Since September CU the issue is resolved also for other browsers.
        Cheers,
        Stefan

        Reply

  5. Hello,

    I am curious, were you able to find a solution, or maybe you opened MSCase and got feedback about it from MS?

    Thanks,
    B

    Reply

  6. Hi Stefan
    We are having issues after this update, the gear menu looks different in a new created site collection. For users with read an edit permissions the menu items are like the classic mode, but for a site owner looks like should do in modern.

    the other thing is when you click on site settings, as a memeber, you are allowed too see all the settings, this wasn’t like this before.

    Do you know if is a known issue and if its resolve in an newer CU ?

    thanks!
    Michel

    Reply

Leave a Reply to Stefan Goßner Cancel reply

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