Patch tracker / KB5087539
KB5087539: Windows 11 Version 25H2 for x64-based Security Update (June 2026)
KB5087539 is a Critical security update for Windows 11 Version 25H2 for x64-based , released 2026-06-09. It closes 66 CVEs with a maximum CVSS of 9.8. The most likely of them to be attacked is CVE-2026-48566, which FIRST.org rates at 80% probability of exploitation in the next 30 days.
Update summary
Fixes 66 CVEs. Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 80%. Among the top 10% of tracked Microsoft updates by EPSS exploit probability.
Microsoft documents 2 known issues with this update.
- Devices with an unrecommended BitLocker Group Policy configuration might be required to enter their BitLocker recovery key
- Windows Server Update Services (WSUS) does not display error details
KB5087539 is a large June 2026 rollup fixing 66 CVEs for Windows 11 25H2 (x64 and ARM64) and Windows Server 2025 Server Core, topped by a Critical flaw at CVSS 9.8 with an EPSS of 80 percent that signals a high probability of exploitation in the wild. Nothing here is on the CISA KEV list or tied to ransomware yet, but an 80 percent EPSS on an unauthenticated-grade score means attackers are likely already probing. Server Core Server 2025 hosts and ARM64 Windows 11 fleets are both in scope, so this is not a client-only patch.
Do this: Deploy KB5087539 to your Windows Server 2025 Server Core and Windows 11 25H2 systems now, prioritizing the CVSS 9.8 Critical fix given its 80 percent EPSS.
AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5087539
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5087539
- Released
- 2026-06-09
- Last changed
- 2026-07-24
- 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 KB5087539 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5087539 (checked 2026-08-05). Verify against the article before acting.
Devices with an unrecommended BitLocker Group Policy configuration might be required to enter their BitLocker recovery key
Symptom
Some devices with an unrecommended BitLocker Group Policy configuration might be required to enter their BitLocker recovery key on the first restart after installing this update.
This issue only affects a limited number of systems in which ALL of the following conditions are true. These conditions are unlikely to be found on personal devices not managed by IT departments.
BitLocker is enabled on the OS drive.
The Group Policy " Configure TPM platform validation profile for native UEFI firmware configurations " is configured, and PCR7 is included in the validation profile (or the equivalent registry key is set manually).
System Information ( msinfo32.exe ) reports Secure Boot State PCR7 Binding as " Not Possible ".
The Windows UEFI CA 2023 certificate is present in the device’s Secure Boot Signature Database (DB), making the device eligible for the 2023‑signed Windows Boot Manager to be made the default.
The device is not already running the 2023-signed Windows Boot Manager.
In this scenario, the BitLocker recovery key only needs to be entered once -- subsequent restarts will not trigger a BitLocker recovery screen, as long as the group policy configuration remains unchanged. For help finding your BitLocker recovery key, see the article, Find your ...
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 | 80% | No |
| CVE-2026-21530 | Critical | 9.8 | 80% | No |
| CVE-2026-32161 | Critical | 9.8 | 80% | No |
| CVE-2026-32170 | Critical | 9.8 | 80% | No |
| CVE-2026-32209 | Critical | 9.8 | 80% | No |
| CVE-2026-33834 | Critical | 9.8 | 80% | No |
| CVE-2026-33835 | Critical | 9.8 | 80% | No |
| CVE-2026-33837 | Critical | 9.8 | 80% | No |
| CVE-2026-33838 | Critical | 9.8 | 80% | No |
| CVE-2026-33839 | Critical | 9.8 | 80% | No |
| CVE-2026-33840 | Critical | 9.8 | 80% | No |
| CVE-2026-33841 | Critical | 9.8 | 80% | No |
| CVE-2026-34329 | Critical | 9.8 | 80% | No |
| CVE-2026-34330 | Critical | 9.8 | 80% | No |
| CVE-2026-34331 | Critical | 9.8 | 80% | No |
| CVE-2026-34332 | Critical | 9.8 | 80% | No |
| CVE-2026-34333 | Critical | 9.8 | 80% | No |
| CVE-2026-34334 | Critical | 9.8 | 80% | No |
| CVE-2026-34336 | Critical | 9.8 | 80% | No |
| CVE-2026-34337 | Critical | 9.8 | 80% | No |
| CVE-2026-34338 | Critical | 9.8 | 80% | No |
| CVE-2026-34339 | Critical | 9.8 | 80% | No |
| CVE-2026-34340 | Critical | 9.8 | 80% | No |
| CVE-2026-34341 | Critical | 9.8 | 80% | No |
| CVE-2026-34342 | Critical | 9.8 | 80% | No |
| CVE-2026-34343 | Critical | 9.8 | 80% | No |
| CVE-2026-34344 | Critical | 9.8 | 80% | No |
| CVE-2026-34345 | Critical | 9.8 | 80% | No |
| CVE-2026-34347 | Critical | 9.8 | 80% | No |
| CVE-2026-34350 | Critical | 9.8 | 80% | No |
| CVE-2026-34351 | Critical | 9.8 | 80% | No |
| CVE-2026-35415 | Critical | 9.8 | 80% | No |
| CVE-2026-35416 | Critical | 9.8 | 80% | No |
| CVE-2026-35417 | Critical | 9.8 | 80% | No |
| CVE-2026-35418 | Critical | 9.8 | 80% | No |
| CVE-2026-35419 | Critical | 9.8 | 80% | No |
| CVE-2026-35420 | Critical | 9.8 | 80% | No |
| CVE-2026-35421 | Critical | 9.8 | 80% | No |
| CVE-2026-35422 | Critical | 9.8 | 80% | No |
| CVE-2026-35423 | Critical | 9.8 | 80% | No |
| CVE-2026-35424 | Critical | 9.8 | 80% | No |
| CVE-2026-40369 | Critical | 9.8 | 80% | No |
| CVE-2026-40377 | Critical | 9.8 | 80% | No |
| CVE-2026-40380 | Critical | 9.8 | 80% | No |
| CVE-2026-40382 | Critical | 9.8 | 80% | No |
| CVE-2026-40397 | Critical | 9.8 | 80% | No |
| CVE-2026-40398 | Critical | 9.8 | 80% | No |
| CVE-2026-40399 | Critical | 9.8 | 80% | No |
| CVE-2026-40401 | Critical | 9.8 | 80% | No |
| CVE-2026-40403 | Critical | 9.8 | 80% | No |
| CVE-2026-40405 | Critical | 9.8 | 80% | No |
| CVE-2026-40406 | Critical | 9.8 | 80% | No |
| CVE-2026-40407 | Critical | 9.8 | 80% | No |
| CVE-2026-40408 | Critical | 9.8 | 80% | No |
| CVE-2026-40410 | Critical | 9.8 | 80% | No |
| CVE-2026-40413 | Critical | 9.8 | 80% | No |
| CVE-2026-40414 | Critical | 9.8 | 80% | No |
| CVE-2026-40415 | Critical | 9.8 | 80% | No |
| CVE-2026-41088 | Critical | 9.8 | 80% | No |
| CVE-2026-41089 | Critical | 9.8 | 80% | No |
| CVE-2026-41095 | Critical | 9.8 | 80% | No |
| CVE-2026-41096 | Critical | 9.8 | 80% | No |
| CVE-2026-41097 | Critical | 9.8 | 80% | No |
| CVE-2026-42825 | Critical | 9.8 | 80% | No |
| CVE-2026-42896 | Critical | 9.8 | 80% | No |
| CVE-2026-48566 | Critical | 9.8 | 80% | No |
Scope and sources
- Affected products
- Also released in June 2026
KB5094139
8 CVEs · High · exploitedKB5094140
8 CVEs · High · exploitedKB5094142
8 CVEs · High · exploitedKB5094144
8 CVEs · High · exploitedKB5087423
66 CVEs · CriticalKB5089466
61 CVEs · CriticalKB5089549
61 CVEs · CriticalKB5093998
158 CVEs · CriticalThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.