Windows Management Services Elevation of Privilege Vulnerability
This high-severity Microsoft Server advisory covers CVE-2026-20866 affecting Windows Server 2019 (Server Core installation), Windows Server 2022, 23H2 Edition (Server Core installation), Windows Server 2025 (Server Core installation).
Android app · Google Play
Monitor future Microsoft Server CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Management Services allows an authorized attacker to elevate privileges locally.
Affected products named by the advisory: Windows Server 2019; Windows Server 2019 (Server Core installation); Windows Server 2022; Windows Server 2022, 23H2 Edition (Server Core installation); and 2 more.
Affected products named by the advisory: Windows Server 2025 (Server Core installation).
- Windows 10 Version 1809 10.0.17763.0 before 10.0.17763.8276
- Windows 10 Version 21H2 10.0.19044.0 before 10.0.19044.6809
- Windows 10 Version 22H2 10.0.19045.0 before 10.0.19045.6809
- Windows 11 version 23H2 10.0.22631.0 before 10.0.22631.6491
- Windows 11 Version 23H2 10.0.22631.0 before 10.0.22631.6491
- Windows 11 Version 24H2 10.0.26100.0 before 10.0.26100.7623
- Windows 11 Version 25H2 10.0.26200.0 before 10.0.26200.7623
- Windows Server 2019 10.0.17763.0 before 10.0.17763.8276
- Windows Server 2019 (Server Core installation) 10.0.17763.0 before 10.0.17763.8276
- Windows Server 2022 10.0.20348.0 before 10.0.20348.4648
- Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.0 before 10.0.25398.2092
- Windows Server 2025 10.0.26100.0 before 10.0.26100.32230
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
- 10.0.17763.8276
- 10.0.19044.6809
- 10.0.19045.6809
- 10.0.22631.6491
- 10.0.26100.7623
- 10.0.26200.7623
- 10.0.20348.4648
- 10.0.25398.2092
- 10.0.26100.32230
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Mitigation
Upgrade to a fixed release: 10.0.17763.8276, 10.0.19044.6809, 10.0.19045.6809, 10.0.22631.6491, 10.0.26100.7623, 10.0.26200.7623. That is the remediation for this advisory.
The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.