Patch tracker / KB5074204
KB5074204: Windows Server 2025 Security Update (December 2025)
KB5074204 is a High security update for Windows Server 2025, released 2025-12-09. It closes 1 CVE with a maximum CVSS of 7.8. It is the 29th largest of the 36 updates Microsoft shipped that month, by CVEs closed.
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Update summary
Fixes 1 CVE. Most severe CVSS 7.8 (High). EPSS exploit probability up to 2.2%. Among the top half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Windows Server 2025 (Server Core installation) has shipped since this one: KB5126646 (2026-10-13). 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.
KB5074204 is a December 9, 2025 update for Windows 10 Version 1809 and Windows Server 2019 that patches a single flaw, CVE-2025-54100, rated High at CVSS 7.8. The 7.8 score with a 2 percent EPSS points to a local privilege escalation style issue rather than remote wormable exploitation, and it is not in CISA KEV nor tied to ransomware. Server 2019 domain controllers and remaining 1809 endpoints are the exposed population.
Do this: Deploy KB5074204 to your Server 2019 and Windows 10 1809 systems through your normal December patch ring, prioritizing multi-user servers where local privilege escalation matters most.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5074204
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5074204
- 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 KB5074204 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-2025-54100 | High | 7.8 | 4.6% | No |
Scope and sources
- Affected products
- Also released in December 2025
KB5071413
28 CVEs · High · exploitedKB5071417
30 CVEs · High · exploitedKB5071542
30 CVEs · High · exploitedKB5071544
26 CVEs · High · exploitedKB5071546
28 CVEs · High · exploitedKB5071547
29 CVEs · High · exploitedKB5072014
33 CVEs · High · exploitedKB5072033
34 CVEs · High · 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.