KB5071542

Microsoft security update released 2025-12-09. Fixes 30 CVEs.

HighCISA KEV

Download KB5071542

Get the official update for KB5071542. The download and file size for each supported product are on the Microsoft Update Catalog page.

Microsoft Update Catalog: download KB5071542 Microsoft support article

Update summary

Released

2025-12-09

CVEs fixed

Max CVSS

8.8

Severity

High

Exploitation and severity

Fixes 30 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 8.8 (High). EPSS exploit probability up to 2.3%.

Among the lower 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 KB5071542 is missing on your devices.

Affected products

Windows 10 Version 1809 for 32-bit Systems
Windows 11 Version 25H2 for ARM64-based Systems
Windows 11 Version 25H2 for x64-based Systems

References

Microsoft support article Microsoft Security Update Guide

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