KB5066873

Microsoft security update released 2025-10-14. Fixes 51 CVEs.

HighCISA KEV

Download KB5066873

Get the official update for KB5066873. The download and file size for each supported product are on the Microsoft Update Catalog page.

Microsoft Update Catalog: download KB5066873 Microsoft support article

Update summary

Released

2025-10-14

CVEs fixed

Max CVSS

8.8

Severity

High

Exploitation and severity

Fixes 51 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 8.8 (High). EPSS exploit probability up to 5.8%.

Among the top half of tracked Microsoft updates by EPSS exploit probability.

What to do

Treat as urgent: it is being exploited in the wild (CISA KEV), so patch ahead of items that are not. Senserva flags whether KB5066873 is missing on your devices.

Affected products

Windows 10 Version 1809 for x64-based Systems
Windows 11 Version 25H2 for x64-based Systems
Windows Server 2019

References

Microsoft support article Microsoft Security Update Guide

See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.