CVE-2026-87705

Undergoing Analysis Undergoing Analysis - In Progress

Improper Source Verification in Windows Hyper-V

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Improper verification of source of a communication channel in Windows Hyper-V allows an unauthorized attacker to bypass a security feature over an adjacent network.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-10-13

Last Modified

2026-10-16

Generated

2026-10-19

AI Q&A

2026-10-14

EPSS Evaluated

2026-10-18

NVD

CVE-2026-87705

EUVD

EUVD-2026-100072

Affected Vendors & Products

Vendor	Product	Version / Range
Microsoft	Windows	10 Version 1607 10.0.14393.0
Microsoft	Windows	10 Version 1809 10.0.17763.0
Microsoft	Windows	10 Version 21H2 10.0.19044.0
Microsoft	Windows	10 Version 22H2 10.0.19045.0
Microsoft	Windows	11 version 23H2 10.0.22631.0
Microsoft	Windows	11 Version 23H2 10.0.22631.0
Microsoft	Windows	11 Version 24H2 10.0.26100.0
Microsoft	Windows	11 Version 25H2 10.0.26200.0
Microsoft	Windows	11 version 26H1 10.0.28000.0
Microsoft	Windows	11 Version 26H2 10.0.26300.0
Microsoft	Windows	Server 2012 6.2.9200.0
Microsoft	Windows	Server 2012 (Server Core installation) 6.2.9200.0
Microsoft	Windows	Server 2012 R2 6.3.9600.0
Microsoft	Windows	Server 2012 R2 (Server Core installation) 6.3.9600.0
Microsoft	Windows	Server 2016 10.0.14393.0
Microsoft	Windows	Server 2016 (Server Core installation) 10.0.14393.0
Microsoft	Windows	Server 2019 10.0.17763.0
Microsoft	Windows	Server 2019 (Server Core installation) 10.0.17763.0
Microsoft	Windows	Server 2022 10.0.20348.0
Microsoft	Windows	Server 2025 10.0.26100.0
Microsoft	Windows	Server 2025 (Server Core installation) 10.0.26100.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-940	The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.

Attack-Flow Graph

Executive Summary

This vulnerability involves improper verification of the source of a communication channel in Windows Hyper-V. An unauthorized attacker can exploit this to bypass a security feature over an adjacent network.

Impact Analysis

An attacker could bypass security controls in Hyper-V, potentially gaining unauthorized access to systems or data on adjacent networks. This may lead to data breaches or further network compromise.

Compliance Impact

This vulnerability allows unauthorized attackers to bypass security features in Windows Hyper-V over an adjacent network. This could potentially lead to unauthorized access to sensitive data, which may violate compliance requirements under GDPR, HIPAA, or other regulations that mandate strict access controls and data protection measures.

Mitigation Strategies

Apply the latest security updates from Microsoft for Hyper-V components to address the improper verification issue. Monitor Microsoft's security advisories for patches and install them promptly.

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