Patch tracker / KB5002821
KB5002821: Microsoft SharePoint Server 2019 Security Update (December 2025)
KB5002821 is a High security update for Microsoft SharePoint Server 2019, released 2025-12-09. It closes 4 CVEs with a maximum CVSS of 7.8. It is the 41st largest of the 59 updates Microsoft shipped that month, by CVEs closed.
Update summary
Fixes 4 CVEs. Most severe CVSS 7.8 (High). EPSS exploit probability up to <1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Microsoft SharePoint Enterprise Server 2016 has shipped since this one: KB5002882 (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.
KB5002821 is a December 2025 fix bundle covering four CVEs across SharePoint Enterprise Server 2016, SharePoint Server 2019, and Office 2019 32-bit editions, with the worst rated High severity at CVSS 7.8. Anyone running on-premises SharePoint farms or those Office 2019 builds is exposed, and SharePoint servers are attractive targets because they hold shared documents and often sit deep in internal networks. None of the four CVEs are in CISA KEV or tied to ransomware yet, and EPSS peaks at only 1 percent, so this is a patch-on-schedule item rather than an emergency.
Do this: Schedule this update into your next SharePoint 2016/2019 and Office 2019 patch cycle, prioritizing internet-reachable SharePoint front ends first.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5002821
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5002821
- Released
- 2025-12-09
- Last changed
- 2026-07-08
- Changes tracked
- 2
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 KB5002821 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-2025-62558 | High | 7.8 | <1% | No |
| CVE-2025-62559 | High | 7.8 | <1% | No |
| CVE-2025-62562 | High | 7.8 | <1% | No |
| CVE-2025-62555 | High | 7.0 | <1% | No |
Scope and sources
- Affected products
- Also released in December 2025
KB5066586
98 CVEs · Critical · exploitedKB5066780
114 CVEs · Critical · exploitedKB5066782
103 CVEs · Critical · exploitedKB5066791
98 CVEs · Critical · exploitedKB5066793
108 CVEs · Critical · exploitedKB5066835
134 CVEs · Critical · exploitedKB5068779
32 CVEs · Critical · exploitedKB5068781
33 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.