CVE-2026-85840

Undergoing Analysis Undergoing Analysis - In Progress

Information Disclosure in Windows Event Viewer

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Files or directories accessible to external parties in Windows Event Viewer allows an authorized attacker to disclose information over a network.

CVSS Scores

EPSS Scores

Probability:
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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-2026-85840

EUVD

EUVD-2026-99547

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-552	The product makes files or directories accessible to unauthorized actors, even though they should not be.

Attack-Flow Graph

Executive Summary

This vulnerability allows an authorized attacker to access files or directories in Windows Event Viewer that are exposed to external parties. The attacker can then disclose sensitive information over a network without needing elevated privileges.

Impact Analysis

An attacker could exploit this to steal sensitive data logged in Windows Event Viewer, such as system events, errors, or user activities. This may lead to further attacks like credential theft or unauthorized access to systems.

Compliance Impact

This vulnerability could violate compliance requirements by exposing sensitive data, such as user activities or system logs, which may contain personally identifiable information (PII) or protected health information (PHI).

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the vulnerability in Windows Event Viewer. Monitor Microsoft's security advisories for updates and restrict network access to sensitive event logs.

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