KB5089466

Microsoft security update released 2026-06-09. Fixes 61 CVEs.

Critical

Download KB5089466

Get the official update for KB5089466. The download and file size for each supported product are on the Microsoft Update Catalog page.

Microsoft Update Catalog: download KB5089466 Microsoft support article

Update summary

Released

2026-06-09

CVEs fixed

Max CVSS

9.8

Severity

Critical

Exploitation and severity

Fixes 61 CVEs. Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 4.7%.

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

What to do

Elevated priority: high severity or a meaningful exploitation probability, sooner if an affected product is internet-facing. Senserva flags whether KB5089466 is missing on your devices.

CVEs fixed by this update

CVE-2025-54518 CVE-2026-21530 CVE-2026-32161 CVE-2026-32170 CVE-2026-32209 CVE-2026-33834 CVE-2026-33835 CVE-2026-33837 CVE-2026-33838 CVE-2026-33839 CVE-2026-33840 CVE-2026-33841 CVE-2026-34329 CVE-2026-34330 CVE-2026-34331 CVE-2026-34333 CVE-2026-34334 CVE-2026-34336 CVE-2026-34337 CVE-2026-34338 CVE-2026-34339 CVE-2026-34340 CVE-2026-34341 CVE-2026-34342 CVE-2026-34343 CVE-2026-34344 CVE-2026-34345 CVE-2026-34347 CVE-2026-34351 CVE-2026-35415 CVE-2026-35416 CVE-2026-35417 CVE-2026-35418 CVE-2026-35419 CVE-2026-35421 CVE-2026-35422 CVE-2026-35423 CVE-2026-35424 CVE-2026-40369 CVE-2026-40377 CVE-2026-40380 CVE-2026-40382 CVE-2026-40397 CVE-2026-40398 CVE-2026-40399 CVE-2026-40401 CVE-2026-40403 CVE-2026-40405 CVE-2026-40406 CVE-2026-40407 CVE-2026-40408 CVE-2026-40410 CVE-2026-40413 CVE-2026-40414 CVE-2026-40415 CVE-2026-41088 CVE-2026-41096 CVE-2026-41097 CVE-2026-42825 CVE-2026-42896 CVE-2026-48566

Affected products

Windows 11 Version 25H2 for ARM64-based Systems
Windows 11 Version 25H2 for x64-based Systems
Windows Server 2025 (Server Core installation)

References

Microsoft support article Microsoft Security Update Guide

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