CVE-2026-81971

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Race Condition in Windows NTFS Elevates Privileges

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows NTFS allows an authorized attacker to elevate privileges locally.

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-2026-81971

EUVD

EUVD-2026-99901

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-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
CWE-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Attack-Flow Graph

Executive Summary

This is a race condition vulnerability in Windows NTFS where improper synchronization during concurrent execution allows an authorized attacker to elevate their privileges locally.

Detection Guidance

Detecting this race condition in NTFS requires monitoring for unusual privilege escalation patterns. Use Event Viewer to check for unexpected privilege changes in Security logs. Commands like 'wevtutil qe Security /q:*[System[(EventID=4672)]]' can help identify privilege assignments. Monitor for multiple concurrent file operations in high-privilege directories.

Impact Analysis

An attacker could exploit this to gain higher-level access on your system, potentially allowing them to install programs, view or delete data, or create new accounts with full user rights.

Compliance Impact

This vulnerability allows local privilege escalation via a race condition in NTFS, which could enable unauthorized access to sensitive data or system functions. For GDPR, this may lead to unauthorized data access or processing violations. For HIPAA, it could compromise protected health information integrity or confidentiality if exploited on systems handling such data.

Mitigation Strategies

Apply the latest Windows security updates immediately through Windows Update or WSUS. Restrict local administrator privileges where possible. Monitor for suspicious activity in privileged processes. Disable unnecessary services that interact with NTFS.

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