Race Condition in Windows LSM Enables Local Privilege Escalation

Publication date: 2026-01-13

Last updated on: 2026-01-13

Assigner: Microsoft Corporation

Description

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

CVSS Scores

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Meta Information

Published

2026-01-13

Last Modified

2026-01-13

Generated

2026-07-06

AI Q&A

2026-01-14

EPSS Evaluated

2026-07-05

NVD

CVE-2026-20869

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_local_session_manager	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
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

Impact Analysis

An attacker who already has some level of authorization on the system can exploit this vulnerability to gain higher privileges than intended. This elevation of privilege can lead to unauthorized actions, potentially compromising system security and integrity. [1]

Executive Summary

This vulnerability is a race condition in the Windows Local Session Manager (LSM) where concurrent execution using a shared resource lacks proper synchronization. This flaw allows an authorized attacker to elevate their privileges locally on the affected system. [1]

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