Patch tracker / KB5002863
KB5002863: Microsoft SharePoint Server 2019 Security Update (May 2026)
KB5002863 is a High security update for Microsoft SharePoint Server 2019, released 2026-05-12. It closes 9 CVEs with a maximum CVSS of 8.8. At least one of them is actively exploited (CISA KEV) and linked to ransomware, so this is a deploy-first update. The most likely of them to be attacked is CVE-2026-35439, which FIRST.org rates at 9% probability of exploitation in the next 30 days.
Update summary
Fixes 9 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 8.8 (High). EPSS exploit probability up to 9.1%. One is linked to ransomware. Among the top half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Microsoft SharePoint Enterprise Server 2016 has shipped since this one: KB5002873 (2026-07-14). 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.
We checked Microsoft's support article for KB5002863 on 2026-08-06 and it lists no known issues. Read the article before broad deployment; Microsoft adds issues as reports come in, and we re-check on every refresh.
KB5002863 is the May 2026 SharePoint update covering Enterprise Server 2016, Server 2019, and Subscription Edition, patching 9 CVEs with a peak severity of High (CVSS 8.8). One of these CVEs is listed in the CISA KEV catalog, meaning it is already being exploited in the wild, though none are tied to ransomware yet. On-premises SharePoint farms are notoriously exposed because they are often internet-facing and hard to patch quickly.
Do this: Apply KB5002863 to all on-premises SharePoint 2016, 2019, and Subscription Edition servers now, prioritizing the known-exploited CVE.
AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5002863
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5002863
- Released
- 2026-05-12
- Last changed
- 2026-08-10
- Changes tracked
- 5
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.
Check if KB5002863 is installed
Elevated PowerShell. No output means it is not installed.
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-2026-45659 | High | 8.8 | 9.1% | KEV Ransomware |
| CVE-2026-33110 | High | 8.8 | 9.1% | No |
| CVE-2026-33112 | High | 8.8 | 9.1% | No |
| CVE-2026-35439 | High | 8.8 | 9.1% | No |
| CVE-2026-40357 | High | 8.8 | 9.1% | No |
| CVE-2026-40365 | High | 8.8 | 9.1% | No |
| CVE-2026-40367 | High | 8.8 | 9.1% | No |
| CVE-2026-40368 | High | 8.8 | 9.1% | No |
| CVE-2026-47294 | High | 8.8 | 9.1% | No |
Scope and sources
- Affected products
- Also released in May 2026
KB5002868
9 CVEs · High · exploitedKB5002870
9 CVEs · High · exploitedKB5078943
3 CVEs · CriticalKB5087420
56 CVEs · CriticalKB5087424
56 CVEs · CriticalKB5087470
39 CVEs · CriticalKB5087471
42 CVEs · CriticalKB5087537
47 CVEs · CriticalThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.