CVE-2025-49751: Windows Hyper-V Denial of Service Vulnerability

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-12 · updated 2026-06-17
Weakness: CWE-820

Description

Missing synchronization in Windows Hyper-V allows an authorized attacker to deny service over an adjacent network.

Affected products

Microsoft Windows 10 1607: before 10.0.14393.8330 — fixed in 10.0.14393.8330
Microsoft Windows 10: before 10.0.17763.7678 — fixed in 10.0.17763.7678
Microsoft Windows 10: before 10.0.19044.6216 — fixed in 10.0.19044.6216
Microsoft Windows 10: before 10.0.19045.6216 — fixed in 10.0.19045.6216
Microsoft Windows 11: before 10.0.22621.5768 — fixed in 10.0.22621.5768
Microsoft Windows 11: before 10.0.22631.5768 — fixed in 10.0.22631.5768
Microsoft Windows 11: before 10.0.26100.4851 — fixed in 10.0.26100.4851
Microsoft Windows Server 2016: before 10.0.14393.8330 — fixed in 10.0.14393.8330
Microsoft Windows Server 2019: before 10.0.17763.7678 — fixed in 10.0.17763.7678
Microsoft Windows Server 2022: before 10.0.20348.3989 — fixed in 10.0.20348.3989
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): before 10.0.25398.1791 — fixed in 10.0.25398.1791
Microsoft Windows Server 2025: before 10.0.26100.4851 — fixed in 10.0.26100.4851
Microsoft Windows 10 1607: from 10.0.14393.0 before 10.0.14393.8330 — fixed in 10.0.14393.8330
Microsoft Windows 10: from 10.0.17763.0 before 10.0.17763.7678 — fixed in 10.0.17763.7678
Microsoft Windows 10: from 10.0.19044.0 before 10.0.19044.6216 — fixed in 10.0.19044.6216
Microsoft Windows 10: from 10.0.19045.0 before 10.0.19045.6216 — fixed in 10.0.19045.6216
Microsoft Windows 11: from 10.0.22621.0 before 10.0.22621.5768 — fixed in 10.0.22621.5768
Microsoft Windows 11 version 22H3: from 10.0.22631.0 before 10.0.22631.5768 — fixed in 10.0.22631.5768
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.5768 — fixed in 10.0.22631.5768
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.4946 — fixed in 10.0.26100.4946
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.8330 — fixed in 10.0.14393.8330
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.7678 — fixed in 10.0.17763.7678
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.4052 — fixed in 10.0.20348.4052
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): from 10.0.25398.0 before 10.0.25398.1791 — fixed in 10.0.25398.1791
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.4946 — fixed in 10.0.26100.4946

How to fix

Upgrade to a fixed version: Microsoft Windows 10 1607 10.0.14393.8330; Microsoft Windows 10 10.0.17763.7678; Microsoft Windows 10 10.0.19044.6216; Microsoft Windows 10 10.0.19045.6216; Microsoft Windows 11 10.0.22621.5768; Microsoft Windows 11 10.0.22631.5768; Microsoft Windows 11 10.0.26100.4851; Microsoft Windows Server 2016 10.0.14393.8330; Microsoft Windows Server 2019 10.0.17763.7678; Microsoft Windows Server 2022 10.0.20348.3989; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.1791; Microsoft Windows Server 2025 10.0.26100.4851. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49751

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