Patch tracker / KB5002883
KB5002883: Microsoft SharePoint Server 2019 Security Update (July 2026)
KB5002883 is a Critical security update for Microsoft SharePoint Server 2019, released 2026-07-14. It closes 39 CVEs with a maximum CVSS of 9.8. At least one of them is actively exploited (CISA KEV), so it is urgent, and Microsoft lists 1 known issue: test it before broad deployment. The most likely of them to be attacked is CVE-2026-50522, which FIRST.org rates at 70% probability of exploitation in the next 30 days.
Before you deploy: Microsoft lists 1 known issue for this update.
Our data comes from Microsoft, CISA and other public sources, and it can be wrong or out of date. If you are unsure, check the linked source before you act, and tell us when we are wrong so we can fix it.
Update summary
Fixes 39 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 70%. Among the top 10% of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Microsoft SharePoint Server 2019 has shipped since this one: KB5002894 (2026-08-11). For cumulative update families the newer package includes these fixes, so installing that one is usually the shorter path. Verify against your own update rings before you skip this package.
Microsoft documents 1 known issue with this update.
- Customers in multi-front-end SharePoint farms with Trusted Provider or Forms authentication may face repeated authentication prompts or multiple...
KB5002883 is a July 2026 SharePoint update patching 39 CVEs across SharePoint Enterprise Server 2016, Server 2019, and Subscription Edition, topped by a Critical flaw at CVSS 9.8. One of these CVEs is on the CISA KEV list, meaning attackers are already exploiting it in the wild, and the highest EPSS of 57 percent signals elevated near-term exploitation likelihood. On-premises SharePoint farms are internet-reachable in many environments, making this a direct target rather than a theoretical risk.
Do this: Prioritize deploying KB5002883 to all on-premises SharePoint 2016, 2019, and Subscription Edition servers now given the confirmed KEV-listed exploited CVE.
AI-generated from public data, 2026-07-25. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5002883
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5002883
- Released
- 2026-07-14
- Last changed
- 2026-10-05
- Changes tracked
- 9
Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.
Microsoft revised KB5002883 on 2026-10-05: CVEs fixed 40 to 39.
- 2026-08-11 CVEs fixed 39 to 40
- 2026-10-05 CVEs fixed 40 to 39
Recorded by Senserva on the dates shown, from the MSRC release feed. This is what moved and when, which neither the vendor advisory nor NVD publishes.
Check if KB5002883 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5002883 (checked 2026-10-15). Microsoft lists 1 known issue. Verify against the article before acting.
Customers in multi-front-end SharePoint farms with Trusted Provider or Forms authentication may face repeated authentication prompts or multiple sign-ins. This should not impact customers who have configured farms with Windows authentication. As a mitigation, configuring sticky sessions on the reverse proxy will address the majority of scenarios. Microsoft is working on a fix in the subsequent product update. While disabling SessionCookieTransformProtectionEnabled may appear to work around the issue, Microsoft does not recommend it. This setting safeguards authentication and turning it off can expose the farm to security vulnerabilities.
When a workflow status link is selected, WrkStat.aspx displays the following error message:
The WorkflowInstanceID parameter is invalid.
To workaround this issue, see Workflow status links fail after installing the July 2026 CU.
CVEs fixed by this update
Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.
| CVE | Severity | CVSS | EPSS | Exploited |
|---|---|---|---|---|
| CVE-2026-50522 | Critical | 9.8 | 70% | KEV |
| CVE-2026-55040 | Critical | 9.1 | 70% | KEV |
| CVE-2026-56164 | Medium | 5.3 | 70% | KEV |
| CVE-2026-55052 | High | 8.8 | 70% | No |
| CVE-2026-58277 | High | 8.8 | 70% | No |
| CVE-2026-55045 | High | 8.4 | 70% | No |
| CVE-2026-55032 | High | 7.8 | 70% | No |
| CVE-2026-55033 | High | 7.8 | 70% | No |
| CVE-2026-55038 | High | 7.8 | 70% | No |
| CVE-2026-55055 | High | 7.8 | 70% | No |
| CVE-2026-55125 | High | 7.8 | 70% | No |
| CVE-2026-55127 | High | 7.8 | 70% | No |
| CVE-2026-55128 | High | 7.8 | 70% | No |
| CVE-2026-55130 | High | 7.8 | 70% | No |
| CVE-2026-55132 | High | 7.8 | 70% | No |
| CVE-2026-55134 | High | 7.8 | 70% | No |
| CVE-2026-55021 | High | 7.3 | 70% | No |
| CVE-2026-55034 | High | 7.3 | 70% | No |
| CVE-2026-55126 | High | 7.3 | 70% | No |
| CVE-2026-54108 | Medium | 6.5 | 70% | No |
| CVE-2026-55051 | Medium | 6.5 | 70% | No |
| CVE-2026-55026 | Medium | 6.2 | 70% | No |
| CVE-2026-55023 | Medium | 5.5 | 70% | No |
| CVE-2026-55027 | Medium | 5.5 | 70% | No |
| CVE-2026-55028 | Medium | 5.5 | 70% | No |
| CVE-2026-55035 | Medium | 5.5 | 70% | No |
| CVE-2026-55047 | Medium | 5.5 | 70% | No |
| CVE-2026-55050 | Medium | 5.5 | 70% | No |
| CVE-2026-55121 | Medium | 5.5 | 70% | No |
| CVE-2026-55124 | Medium | 5.5 | 70% | No |
| CVE-2026-55142 | Medium | 5.5 | 70% | No |
| CVE-2026-56192 | Medium | 5.5 | 70% | No |
| CVE-2026-56157 | Medium | 5.4 | 70% | No |
| CVE-2026-55016 | Medium | 4.6 | 70% | No |
| CVE-2026-55019 | Medium | 4.6 | 70% | No |
| CVE-2026-55020 | Medium | 4.6 | 70% | No |
| CVE-2026-55030 | Medium | 4.6 | 70% | No |
| CVE-2026-55135 | Medium | 4.6 | 70% | No |
| CVE-2026-62826 | Medium | 4.6 | 70% | No |
Scope and sources
- Affected products
- Also released in July 2026
KB5099444
186 CVEs · Critical · exploitedKB5099445
175 CVEs · Critical · exploitedKB5099535
262 CVEs · Critical · exploitedKB5099536
388 CVEs · Critical · exploitedKB5099538
312 CVEs · Critical · exploitedKB5099539
314 CVEs · Critical · exploitedKB5099540
326 CVEs · Critical · exploitedKB5101649
382 CVEs · Critical · exploitedThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.