July 2026 CU for SharePoint Server 2016 is available for download

29 Comments

1. 

   Neil King
   On 15. July 2026 Permalink

   Will this be the last CU for SharePoint 2016 no its out of Extended support

   Reply
   1. 

      Stefan Goßner
      On 15. July 2026 Permalink

      Hi Neil,
      there is no guarantee as in some cases even after end of support additional critical security fixes can be made available.
      Cheers,
      Stefan

      Reply
2. 

   Walter
   On 15. July 2026 Permalink

   hi,
   are there any known problems with the july updtaes? after installing the updates onenote online and online office apps are no longer working (can not open document…)

   regards
   walter

   Reply
   1. 

      Alexander
      On 16. July 2026 Permalink

      yeah same

      Reply
   2. 

      Jude Buddle
      On 17. July 2026 Permalink

      Hi Stefan,

      I’m seeing the same behaviour with OOS as reported by others after applying the July updates though the wording in ULS logs seems to vary. SharePoint ULS for one farm were as reported re: security tokens but another 2016 farm shows “Self-issued token request for ‘wopi/oos.fqdn.com@GUID’ succeeded”. OOS ULS for both farms ultimately show “WOPI CheckFile: Catch-All Failure exception:Microsoft.Office.Web.Common.EnvironmentAdapters.WopiUserUnauthorizedException: WOPI 401 —> System.Web.HttpException: Unauthorized”.

      The only workaround appears to be to open the file in the Office client rather than the browser.

      Regards,

      Reply
3. 

   walter
   On 16. July 2026 Permalink

   Hi Stefan,

   We are experiencing an issue with our SharePoint Server 2016 environment after installing the July 2026 Security Update KB5002891 (Build 16.0.5561.1001). Following the update, Office and OneNote documents can no longer be viewed or edited in the browser through Office Online Server (OOS). The issue is fully reproducible.

   After opening a Word, Excel, or OneNote document in the browser, OOS reports:
   Could not contact WOPI End Point.
   Error details – ‘Unauthorized url’

   At the same time, the SharePoint ULS logs show the following error:

   SPJsonWebSecurityBaseTokenHandler: ValidateTokenIssuer rejected Issuer
   because no registered STS matches the signing certificate

   System.IdentityModel.Tokens.SecurityTokenException:
   Issuer name is not registered

   is this a known issue after installing KB5002891?

   regrds walter

   Reply
   1. 

      XY
      On 16. July 2026 Permalink

      We are also encountering the same issue.

      Reply
   2. 

      Babu M
      On 16. July 2026 Permalink

      We also facing an issue after updating the July patches. When I open the Office Documents, I’m getting “You do not have permissions to open this file in the browser.” error message.

      Reply
   3. 

      Stefan Goßner
      On 16. July 2026 Permalink

      Hi Walter,
      please try this:

      $farm = Get-SPFarm
      $farm.DisableActorTokenAudienceValidation = $true
      $farm.update ()

      Cheers,
      Stefan

      Reply
      1. 

         Babu M
         On 16. July 2026 Permalink

         Hi Stefan,

         It seems this property doesn’t exist in SP2016. I’m getting “The property ‘DisableActorTokenAudienceValidation’ cannot be found on this object. Verify that the property exists and
         can be set.” error. Kindly check and provide us a workaround to fix this issue.

         Thanks.

         Reply
      2. 

         Walter
         On 16. July 2026 Permalink

         Hello Stefan,
         Unfortunately, it did not work. I am also getting the following error:

         The property ‘DisableActorTokenAudienceValidation’ cannot be found on this object. Verify that the property exists and can be set.

         Regards
         Walter

         Reply
4. 

   Chris
   On 16. July 2026 Permalink

   Also have the same issue

   Reply
5. 

   Markus
   On 16. July 2026 Permalink

   Same Issue here:

   SPJsonWebSecurityBaseTokenHandler: ValidateTokenIssuer rejected Issuer ‘00000003-0000-0ff1-ce00-000000000000@ee790206-b967-4062-89f1-f22d790ce6c9’ because no registered STS matches the signing certificate ‘CN=SharePoint Security Token Service, OU=SharePoint, O=Microsoft, C=US’

   Reply
   1. 

      Stefan Goßner
      On 16. July 2026 Permalink

      Hi Markus,
      please try this:

      $farm = Get-SPFarm
      $farm.DisableActorTokenAudienceValidation = $true
      $farm.update ()

      Cheers,
      Stefan

      Reply
6. 

   Markus
   On 16. July 2026 Permalink

   Same Issue here, for everything opening in Office Online Server: Word, Excel, PDF, Powerpoint…
   As our migration is almost done, this is a good argument to speed up the migration process. We Sharepoint admins won’t fix that. 🙂

   Reply
7. 

   Ciro
   On 16. July 2026 Permalink

   Has anyone identified a potential workaround for this issue?

   Reply
   1. 

      Stefan Goßner
      On 16. July 2026 Permalink

      Hi Ciro,
      please try this:

      $farm = Get-SPFarm
      $farm.DisableActorTokenAudienceValidation = $true
      $farm.update ()

      Cheers,
      Stefan

      Reply
      1. 

         John
         On 16. July 2026 Permalink

         Hi Stefan,

         Are there any security risks implications associated for workaround you mentioned.

         $farm = Get-SPFarm
         $farm.DisableActorTokenAudienceValidation = $true
         $farm.update ()

         Is it safe to implement this workaround?

         Please let us know.

         Reply
         1. 

            Stefan Goßner
            On 16. July 2026 Permalink

            Hi John,

            this “workaround” is actually required and documented in the KB for SPSE for July 2026 CU in the known issue section.
            My guess is that the same applies to SP2016 and SP2019 as the error message is exactly what you will get on SPSE if the setting is not changed.

            Cheers,
            Stefan

            Reply
      2. 

         Bob
         On 16. July 2026 Permalink

         Hi Stefan! Unfortunately there is no property “DisableActorTokenAudienceValidation” for SharePoint 2016 Farm

         Reply
         1. 

            Stefan Goßner
            On 16. July 2026 Permalink

            Hi Bob,
            ok, thanks for checking.
            Cheers,
            Stefan

            Reply
      3. 

         Ciro
         On 16. July 2026 Permalink

         Hello Stefan, Thank you for your quick response. Unfortunately, the issue persists 🙁

         Reply
8. 

   Basha Shaik
   On 16. July 2026 Permalink

   We are also facing an issue after updating the July patches. When I open the Office Documents, I’m getting “You do not have permissions to open this file in the browser.” error message.

   Reply
9. 

   Stefan Goßner
   On 17. July 2026 Permalink

   Hi all,
   we just finished analyzing the OOS issue.
   It is indeed a problem in July 2026 CU for SP2016.
   SP2019 is not affected and for SPSE the property listed above should resolve it.
   Currently no known workaround for SP2016.

   We have involved engineering on this.
   Cheers,
   Stefan

   Reply
10. 

    Jude Buddle
    On 17. July 2026 Permalink

    This may not be considered a viable option for everyone, but the workaround we’ve settled on is to modify the behaviour of OOS by running the following commands:

    Remove interactive previews for Word, Excel and PowerPoint so end users aren’t left staring at the “sorry we can’t open this” messaging

    Get-SPWOPIBinding -Extension “DOCX” -Action “interactivepreview” | Remove-SPWOPIBinding -Confirm:$false
    Get-SPWOPIBinding -Extension “XLSX” -Action “interactivepreview” | Remove-SPWOPIBinding -Confirm:$false
    Get-SPWOPIBinding -Extension “PPTX” -Action “interactivepreview” | Remove-SPWOPIBinding -Confirm:$false

    Remove option to Open Word, Excel and PowerPoint in Browser which then forces the Open in Client option

    Get-SPWOPIBinding -Application “Word” -Extension “docx” -Action “view” | Remove-SPWOPIBinding -Confirm:$false
    Get-SPWOPIBinding -Application “Excel” -Extension “xlsx” -Action “view” | Remove-SPWOPIBinding -Confirm:$false
    Get-SPWOPIBinding -Application “PowerPoint” -Extension “pptx” -Action “view” | Remove-SPWOPIBinding -Confirm:$false

    Reply
11. 

    Bob
    On 22. July 2026 Permalink

    Hi Stefan, could you please let us know if there are any updates?

    Reply
    1. 

       Stefan Goßner
       On 22. July 2026 Permalink

       Hi Bob,
       in case you are talking about the SP2016/OOS issue – I will update this blog as soon as there is something new:
       https://blog.stefan-gossner.com/2026/07/17/trending-issue-office-online-server-oos-integration-with-sp2016-fails-after-installing-july-2026-cu/
       Cheers,
       Stefan

       Reply
       1. 

          Bob
          On 23. July 2026 Permalink

          Hi Stefan! Thank you very much!

          Reply
12. 

    Prabhu Natesan
    On 28. July 2026 Permalink

    After installing SP2016 July 2026 CU I am not able to open SP Excel File in Excel App also, facing the below issue.
    “You need permission to access this item.”

    Reply