Patch tracker / KB5071503
KB5071503: Windows Server 2019 Security Update (December 2025)
KB5071503 is a High security update for Windows Server 2019, released 2025-12-09. It closes 11 CVEs with a maximum CVSS of 8.8. It is the 33rd largest of the 59 updates Microsoft shipped that month, by CVEs closed.
Update summary
Fixes 11 CVEs. Most severe CVSS 8.8 (High). EPSS exploit probability up to 2.1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Windows 10 Version 1809 for 32-bit Systems has shipped since this one: KB5094041 (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.
KB5071503 is the December 9, 2025 rollup for Windows 10 version 1809 and Windows Server 2019, closing 11 CVEs with a highest rating of High (CVSS 8.8). None are in CISA KEV or linked to ransomware, and EPSS tops out at 2 percent, so this is a patch-before-it-matters update rather than an active-fire situation. The 1809 and Server 2019 footprint means legacy on-prem and older server estates are the exposed population.
Do this: Schedule KB5071503 into your next Server 2019 and Windows 10 1809 patch ring this cycle rather than deferring to an emergency window.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5071503
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5071503
- 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 KB5071503 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-2025-62549 | High | 8.8 | 4.6% | No |
| CVE-2025-54100 | High | 7.8 | 4.6% | No |
| CVE-2025-62455 | High | 7.8 | 2.4% | No |
| CVE-2025-62458 | High | 7.8 | 2.4% | No |
| CVE-2025-62466 | High | 7.8 | 4.6% | No |
| CVE-2025-62470 | High | 7.8 | 4.6% | No |
| CVE-2025-62472 | High | 7.8 | 4.6% | No |
| CVE-2025-62474 | High | 7.8 | 4.6% | No |
| CVE-2025-62571 | High | 7.8 | 4.6% | No |
| CVE-2025-62473 | Medium | 6.5 | 4.6% | No |
| CVE-2025-62567 | Medium | 5.3 | 4.6% | 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.