OnlyFm252
Role: Windows Hyper-V

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

Important CVSS 6.8 EPSS 0.00426 2025-08 archive

Executive Summary

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

Overview

6.8
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Denial of Service
Released Aug 12 2025
Last Updated Aug 12 2025
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.00426 — 0.33906 percentile
NVD CVSS 6.8 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Adjacent_network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Changed
CONFIDENTIALITY
None
INTEGRITY
None
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 5.9

EPSS Score

0.00426
probability of exploitation in the next 30 days
0.33906 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

13 affected products
Product KB Article Severity Impact Restart Required
Windows 10 Version 1607 for x64-based Systems 5063871 (Security Update) Important Denial of Service Yes
Windows 10 Version 1809 for x64-based Systems 5063877 (Security Update) Important Denial of Service Yes
Windows 10 Version 21H2 for x64-based Systems 5063709 (SecurityUpdate) Important Denial of Service Yes
Windows 10 Version 22H2 for x64-based Systems 5063709 (SecurityUpdate) Important Denial of Service Yes
Windows 11 Version 22H2 for ARM64-based Systems 5063875 (Security Update) Important Denial of Service Yes
Windows 11 Version 22H2 for x64-based Systems 5063875 (Security Update) Important Denial of Service Yes
Windows 11 Version 23H2 for ARM64-based Systems 5063875 (Security Update) Important Denial of Service Yes
Windows 11 Version 23H2 for x64-based Systems 5063875 (Security Update) Important Denial of Service Yes
Windows 11 Version 24H2 for ARM64-based Systems 5063878 (Security Update) 5064010 (SecurityHotpatchUpdate) Important Denial of Service 5062553 Base: 6.8 Temporal: 5.9 Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C 10.0.26100.4946 10.0.26100.4851 Yes None Windows 11 Version 24H2 for x64-based Systems 5063878 (Security Update) 5064010 (SecurityHotpatchUpdate) Important Denial of Service 5062553 Base: 6.8 Temporal: 5.9 Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C 10.0.26100.4946 10.0.26100.4851 Yes None Windows Server 2016 5063871 (Security Update) Important Denial of Service Yes
Windows Server 2016 (Server Core installation) 5063871 (Security Update) Important Denial of Service Yes
Windows Server 2019 5063877 (Security Update) Important Denial of Service Yes
Windows Server 2019 (Server Core installation) 5063877 (Security Update) Important Denial of Service Yes
Windows Server 2022 5063880 (SecurityUpdate) 5063812 (SecurityHotpatchUpdate) Important Denial of Service 5062572 Base: 6.8 Temporal: 5.9 Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C 10.0.20348.4052 10.0.20348.3989 Yes None Windows Server 2022 (Server Core installation) 5063880 (SecurityUpdate) 5063812 (SecurityHotpatchUpdate) Important Denial of Service 5062572 Base: 6.8 Temporal: 5.9 Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C 10.0.20348.4052 10.0.20348.3989 Yes None Windows Server 2022, 23H2 Edition (Server Core installation) 5063899 (SecurityUpdate) Important Denial of Service Yes

Patches

5 patches
Article Type Restart
5063871 Security Update Yes
5063877 Security Update Yes
5063709 SecurityUpdate Yes
5063875 Security Update Yes
5063899 SecurityUpdate Yes

Known Exploits

Acknowledgments

HongZhenhao

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