Patch tracker / KB5089549
KB5089549: Windows 11 Version 25H2 for x64-based Security Update (June 2026)
Updated July 21, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
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Microsoft security update released 2026-06-09. Fixes 61 CVEs.
All about KB5089549: the download, the Senserva AI read, a PowerShell installed-check, install guidance, the CVEs it fixes, and its change history.
KB5089549 is a Critical security update for Windows 11 Version 25H2 for x64-based , released 2026-06-09. It closes 61 CVEs with a maximum CVSS of 9.8. Get it from the Microsoft Update Catalog below, and see where it sits against the rest of the month on the patch tracker.
No exploitation is confirmed for the CVEs in this update and the EPSS exploitation probability is currently 4.7%. That can change: CVEs from past updates regularly get exploited months later, which is why deploying on your normal cadence, without exceptions that linger, is what keeps this one boring.
Most organizations deliver an update like this automatically through Intune update rings, Windows Update for Business, Windows Autopatch, or WSUS; the install section below covers each path. For the bigger picture: how the Microsoft patching tools fit together, this month's Patch Tuesday summary, and every update ranked by real-world risk.
Download KB5089549
Get the official update for KB5089549. The download and file size for each supported product are on the Microsoft Update Catalog page.
Update summary
Senserva AI Opinion for KB5089549
KB5089549 is a large 61 CVE rollup for Windows Server 2025 Server Core and Windows 11 25H2 on both ARM64 and x64, with a top rating of Critical at CVSS 9.8. Nothing here is on the CISA KEV list and EPSS peaks at only 5 percent, so exploitation is not yet observed, but the 9.8 score suggests at least one unauthenticated remote code execution path. The ARM64 coverage and Server Core scope means both edge or cloud instances and lean server builds need this.
Do this: Stage KB5089549 in a test ring covering Server Core, ARM64, and x64 25H2, then prioritize deployment to internet-facing Windows Server 2025 hosts given the Critical 9.8 finding.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5089549
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5089549
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.
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 KB5089549 is missing on your devices.
Check if KB5089549 is installed
Copy-paste PowerShell: one machine, or your whole fleet in one pass. No output means the update is not installed.
Get-HotFix covers Windows updates. Office, SharePoint, and Exchange server updates show under installed updates in Programs and Features, or check the Update Catalog history.
Writing about KB5089549? Cite this page
Copy-paste for a blog post, forum answer, or internal doc. The link always carries the current risk data.
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-2025-54518 | Critical | 9.8 | 72% | No |
| CVE-2026-21530 | Critical | 9.8 | 72% | No |
| CVE-2026-32161 | Critical | 9.8 | 72% | No |
| CVE-2026-32170 | Critical | 9.8 | 72% | No |
| CVE-2026-32209 | Critical | 9.8 | 72% | No |
| CVE-2026-33834 | Critical | 9.8 | 72% | No |
| CVE-2026-33835 | Critical | 9.8 | 72% | No |
| CVE-2026-33837 | Critical | 9.8 | 72% | No |
| CVE-2026-33838 | Critical | 9.8 | 72% | No |
| CVE-2026-33839 | Critical | 9.8 | 72% | No |
| CVE-2026-33840 | Critical | 9.8 | 72% | No |
| CVE-2026-33841 | Critical | 9.8 | 72% | No |
| CVE-2026-34329 | Critical | 9.8 | 72% | No |
| CVE-2026-34330 | Critical | 9.8 | 72% | No |
| CVE-2026-34331 | Critical | 9.8 | 72% | No |
| CVE-2026-34333 | Critical | 9.8 | 72% | No |
| CVE-2026-34334 | Critical | 9.8 | 72% | No |
| CVE-2026-34336 | Critical | 9.8 | 72% | No |
| CVE-2026-34337 | Critical | 9.8 | 72% | No |
| CVE-2026-34338 | Critical | 9.8 | 72% | No |
| CVE-2026-34339 | Critical | 9.8 | 72% | No |
| CVE-2026-34340 | Critical | 9.8 | 72% | No |
| CVE-2026-34341 | Critical | 9.8 | 72% | No |
| CVE-2026-34342 | Critical | 9.8 | 72% | No |
| CVE-2026-34343 | Critical | 9.8 | 72% | No |
| CVE-2026-34344 | Critical | 9.8 | 72% | No |
| CVE-2026-34345 | Critical | 9.8 | 72% | No |
| CVE-2026-34347 | Critical | 9.8 | 72% | No |
| CVE-2026-34351 | Critical | 9.8 | 72% | No |
| CVE-2026-35415 | Critical | 9.8 | 72% | No |
| CVE-2026-35416 | Critical | 9.8 | 72% | No |
| CVE-2026-35417 | Critical | 9.8 | 72% | No |
| CVE-2026-35418 | Critical | 9.8 | 72% | No |
| CVE-2026-35419 | Critical | 9.8 | 72% | No |
| CVE-2026-35421 | Critical | 9.8 | 72% | No |
| CVE-2026-35422 | Critical | 9.8 | 72% | No |
| CVE-2026-35423 | Critical | 9.8 | 72% | No |
| CVE-2026-35424 | Critical | 9.8 | 72% | No |
| CVE-2026-40369 | Critical | 9.8 | 72% | No |
| CVE-2026-40377 | Critical | 9.8 | 72% | No |
| CVE-2026-40380 | Critical | 9.8 | 72% | No |
| CVE-2026-40382 | Critical | 9.8 | 72% | No |
| CVE-2026-40397 | Critical | 9.8 | 72% | No |
| CVE-2026-40398 | Critical | 9.8 | 72% | No |
| CVE-2026-40399 | Critical | 9.8 | 72% | No |
| CVE-2026-40401 | Critical | 9.8 | 72% | No |
| CVE-2026-40403 | Critical | 9.8 | 72% | No |
| CVE-2026-40405 | Critical | 9.8 | 72% | No |
| CVE-2026-40406 | Critical | 9.8 | 72% | No |
| CVE-2026-40407 | Critical | 9.8 | 72% | No |
| CVE-2026-40408 | Critical | 9.8 | 72% | No |
| CVE-2026-40410 | Critical | 9.8 | 72% | No |
| CVE-2026-40413 | Critical | 9.8 | 72% | No |
| CVE-2026-40414 | Critical | 9.8 | 72% | No |
| CVE-2026-40415 | Critical | 9.8 | 72% | No |
| CVE-2026-41088 | Critical | 9.8 | 72% | No |
| CVE-2026-41096 | Critical | 9.8 | 72% | No |
| CVE-2026-41097 | Critical | 9.8 | 72% | No |
| CVE-2026-42825 | Critical | 9.8 | 72% | No |
| CVE-2026-42896 | Critical | 9.8 | 72% | No |
| CVE-2026-48566 | Critical | 9.8 | 72% | No |
Affected products
Also released in June 2026
The highest-risk updates from the same release:
The full month, summarized: Microsoft Patch Tuesday.
How to install KB5089549
Any of these paths delivers KB5089549; most organizations already have one of the first three running:
- Intune update rings (Windows Update for Business): the update flows on each ring's deferral schedule.
- Windows Autopatch: rings, rollout, and pause or rollback are managed for you; exploited updates can be expedited.
- WSUS / Configuration Manager: approve KB5089549 for your device groups and set a deadline.
- Manual: download from the Update Catalog above and install; fine for a handful of machines, unmanageable at any real scale.
After the rollout, verify rather than assume: update compliance reporting in Intune or Autopatch shows which devices actually installed it, and Siemserva reads Intune, Defender, Autopatch, and Azure Update Manager together to show the devices still missing KB5089549, ranked by exploitation.
Common questions about KB5089549
Is KB5089549 urgent?
KB5089549 is rated Critical with a maximum CVSS of 9.8. No active exploitation is confirmed yet, so schedule it in your prompt patch cycle.
How do I download KB5089549?
From the Microsoft Update Catalog (linked on this page), or let Intune, Windows Update for Business, Windows Autopatch, or WSUS deliver it. The catalog page lists the download for each supported product.
How do I deploy KB5089549 with Intune?
Assign a Windows Update ring (quality update policy) to the device groups and the update flows on the ring's deferral schedule. For urgent updates, Intune expedite policies can bypass the ring deferrals. Verify the rollout with update compliance reporting rather than assuming delivery.
Can I ask my own AI about KB5089549?
Yes. This page includes a free, ready-to-paste AI prompt containing KB5089549's key facts: severity, CVE count, exploitation status, and the download link. Copy it into Claude, ChatGPT, or Copilot for a rollout plan; the data is refreshed three times a day (5 AM, 12:30 PM, and 7 PM US Central).
Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.
