Patch tracker / KB5074353
KB5074353: Windows Server 2019 Security Update (December 2025)
KB5074353 is a High security update for Windows Server 2019, released 2025-12-09. It closes 1 CVE with a maximum CVSS of 7.8. It is the 52nd largest of the 59 updates Microsoft shipped that month, by CVEs closed.
Update summary
Fixes 1 CVE. Most severe CVSS 7.8 (High). EPSS exploit probability up to 1.5%. 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.
KB5074353 is a December 2025 update for Windows 10 version 1809 and Windows Server 2019 that patches a single flaw, CVE-2025-54100, rated High with a CVSS of 7.8. The 7.8 score points to local elevation of privilege rather than remote exploitation, so exposure centers on machines where an attacker or malware already has a foothold. It is not in CISA KEV, and the EPSS of 2% suggests exploitation in the wild is currently unlikely.
Do this: Approve KB5074353 for your 1809 and Server 2019 fleet in the next standard patch window rather than issuing an emergency deployment.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5074353
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5074353
- 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 KB5074353 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
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.