CVE-2026-83766

EUVD-2026-99987
Incorrect authorization in Windows Hyper-V allows an authorized attacker to bypass a security feature over an adjacent network.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.2 MEDIUM
ADJACENT_NETWORK
HIGH
HIGH
CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 27.91%
Windows Releases
Platform
Version
Windows 10
1607 (x64)
KB5126868
1809 (x64, x86)
KB5126651
21H2 (arm64, x64, x86)
KB5126657
22H2 (arm64, x64, x86)
KB5126657
Windows 11
23H2 (arm64, x64)
KB5126653
24H2 (arm64, x64)
KB5127648
25H2 (arm64, x64)
KB5127648
26H1 (arm64, x64)
KB5127646
26H2 (arm64, x64)
KB5127648
Windows Server 2016
Server Core
KB5126868
Standard
KB5126868
Windows Server 2019
Server Core
KB5126651
Standard
KB5126651
Windows Server 2022
Server Core
KB5126655
Standard
KB5126655
Windows Server 2025
Server Core
KB5126646
Standard
KB5126646
Common Weakness Enumeration
References
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83766