Patch tracker / KB5002883
KB5002883: Microsoft SharePoint Server 2019 Security Update (August 2026)
KB5002883 is a Critical security update for Microsoft SharePoint Server 2019, released 2026-08-11. It closes 40 CVEs with a maximum CVSS of 9.8. At least one of them is actively exploited (CISA KEV), so this is a deploy-first update. The most likely of them to be attacked is CVE-2026-70306, which FIRST.org rates at 77% probability of exploitation in the next 30 days.
Update summary
Fixes 40 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 77%. Among the top 10% of tracked Microsoft updates by EPSS exploit probability.
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
- 2026-08-11
- Changes tracked
- 6
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.
On 2026-08-11, Senserva recorded the CVE count for KB5002883 rising from 39 to 40, the strongest and only signal in this trail. This single upward move means the update now addresses one additional vulnerability, so treat it as current and prioritize deployment today.
- 2026-08-11 CVEs fixed 39 to 40
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 2026-08-11). 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 | 77% | KEV |
| CVE-2026-56164 | Medium | 5.3 | 77% | KEV |
| CVE-2026-70306 | Critical | 9.3 | 77% | No |
| CVE-2026-55040 | Critical | 9.1 | 77% | No |
| CVE-2026-55052 | High | 8.8 | 77% | No |
| CVE-2026-58277 | High | 8.8 | 77% | No |
| CVE-2026-55045 | High | 8.4 | 77% | No |
| CVE-2026-55032 | High | 7.8 | 77% | No |
| CVE-2026-55033 | High | 7.8 | 77% | No |
| CVE-2026-55038 | High | 7.8 | 77% | No |
| CVE-2026-55055 | High | 7.8 | 77% | No |
| CVE-2026-55125 | High | 7.8 | 77% | No |
| CVE-2026-55127 | High | 7.8 | 77% | No |
| CVE-2026-55128 | High | 7.8 | 77% | No |
| CVE-2026-55130 | High | 7.8 | 77% | No |
| CVE-2026-55132 | High | 7.8 | 77% | No |
| CVE-2026-55134 | High | 7.8 | 77% | No |
| CVE-2026-55021 | High | 7.3 | 77% | No |
| CVE-2026-55034 | High | 7.3 | 77% | No |
| CVE-2026-55126 | High | 7.3 | 77% | No |
| CVE-2026-54108 | Medium | 6.5 | 77% | No |
| CVE-2026-55051 | Medium | 6.5 | 77% | No |
| CVE-2026-55026 | Medium | 6.2 | 77% | No |
| CVE-2026-55023 | Medium | 5.5 | 77% | No |
| CVE-2026-55027 | Medium | 5.5 | 77% | No |
| CVE-2026-55028 | Medium | 5.5 | 77% | No |
| CVE-2026-55035 | Medium | 5.5 | 77% | No |
| CVE-2026-55047 | Medium | 5.5 | 77% | No |
| CVE-2026-55050 | Medium | 5.5 | 77% | No |
| CVE-2026-55121 | Medium | 5.5 | 77% | No |
| CVE-2026-55124 | Medium | 5.5 | 77% | No |
| CVE-2026-55142 | Medium | 5.5 | 77% | No |
| CVE-2026-56192 | Medium | 5.5 | 77% | No |
| CVE-2026-56157 | Medium | 5.4 | 77% | No |
| CVE-2026-55016 | Medium | 4.6 | 77% | No |
| CVE-2026-55019 | Medium | 4.6 | 77% | No |
| CVE-2026-55020 | Medium | 4.6 | 77% | No |
| CVE-2026-55030 | Medium | 4.6 | 77% | No |
| CVE-2026-55135 | Medium | 4.6 | 77% | No |
| CVE-2026-62826 | Medium | 4.6 | 77% | No |
What the press says about this update
Trusted-source coverage of the CVEs this update fixes, pulled live from their own feeds.
Scope and sources
- Affected products
- Also released in August 2026
KB5002882
39 CVEs · Critical · exploitedKB5002891
40 CVEs · Critical · exploitedKB5120228
212 CVEs · Critical · exploitedKB5120229
194 CVEs · Critical · exploitedKB5120233
214 CVEs · Critical · exploitedKB5120238
182 CVEs · Critical · exploitedKB5120240
170 CVEs · Critical · exploitedKB5120242
194 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.