For more details check this article: Trending Issue: SharePoint fixes fail to install after installation of September 2025 CU
The product group released the January 2026 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 January 2026 CU should be available at the following locations in a couple of hours:
- KB 5002828 – January 2026 Update for SharePoint Server 2016 (language independent)
This is also a security update! - KB 5002827 – January 2026 Update for SharePoint Server 2016 (language dependent)
This is also a security update!
The downloads for January 2026 CU are available through the following links:
- Download January 2026 Update for SharePoint Server 2016 (language independent)
This is also a security update! - Download January 2026 Update for SharePoint Server 2016 (language dependent)
This is also a security update!
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 January 2026 CU Build Numbers:
Language independent fix: 16.0.5535.1001
Language dependent fix: 16.0.5535.1000
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:
- Technet: Updated Product Servicing Policy for SharePoint Server 2016
- Blog: SharePoint Patching Best Practices
- Blog: Common Question: What is the difference between a PU, a CU and a COD?
- Blog: SharePoint Patching demystified
- Blog: Why I prefer PSCONFIGUI.EXE over PSCONFIG.EXE
- Technet: Update Center for Microsoft Office, Office Servers, and Related Products
- Blog: SharePoint Server 2016 Patch Build Numbers Powershell Module
- Blog: SharePoint Server 2016 Zero-Downtime Patching Demystified
- Blog: SharePoint does not have a build version. Full Stop.
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Hi Stefan!
I got problems with a SP2016 farm after applying the Jan patch and wondering if its a known problem?
After patchinstall and run of psconfig the main webapp was not available, reporting access denied 403.
Searching for a solution i found info that it could be a permission problem in registry-hive
HKLM\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\16.0\Secure and entry was missing SP-groups. WSS_ADMIN_WPG and WSS_WPG
I added group and site was up running again.
This is a legacy sp2016, inplace upgraded maybe since sp2010 but it seems strange i have to manually edit permissions on hive? Does the patch change permissions on the registry hive?
Regards,
/M
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Hi Micke,
no I haven’t seen this.
Cheers,
Stefan
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Hi Stefan!
I reviewed the details for KB 5002827 – January 2026 Update for SharePoint Server 2016 (language dependent), and I noticed the note stating:
To get the improvement and fix the issue completely, you have to install KB 5002771 together with this update.
Could you please confirm whether this is a typo?
Normally, a language-dependent update should be installed together with the corresponding language-independent update released in the same month. In this case, I would expect it to reference KB 5002828 – January 2026 language-independent update, rather than KB 5002771 from August 2025.
Why does the January 2026 language-dependent update require a language-independent update from August 2025 instead of its matching January 2026 package?
Best regards,
Leo
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Hi Leo,
yes that seems to be a typo.
Please install 5002828 together with 5002827.
Cheers,
Stefan
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Stefan, there is a specific order to install KB5002828 and KB5002827
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Hi Luis,
not really. Best practice is to install the language independent part first and then the language dependent – but it will also work the other way around.
But it is required to install both of them on each server.
Cheers,
Stefan
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Issue with SharePoint 2016 after applying this CU.
And it seems we are not alone
https://learn.microsoft.com/en-us/answers/questions/5738426/sharepoint-2016-jan-2026-security-update-breaks-cu
DataformWebPart with Soap connection doesn’t work anymore
Failed to GetType for TagMapping tagType soap:Envelope.
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Hi Louis,
yes – this is a known issue. A fix for this is currently in development.
For SharePoint Server Subscription Edition the fix is already included in February 2026 CU – for SP2016 and SP2019 the fix will be released shortly.
Please open a ticket with Microsoft support to be informed when the fix is available.
Cheers,
Stefan
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Temporary fix exists but a support request must be made to Microsoft.
And to deploy the fix we need before to deploy February CU.
So it became complicated to patch SharePoint from many months with all issues generated by each CU.
Maybe it’s time to stop using copilot and leave real developer code the CU 😉
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Hi Louis,
this is not a temporary fix – it is an official hotfix for the issue.
And not the complete February CU is required – only the language dependent one to complement the language independentl fix released for this issue.
Cheers,
Stefan