Windows USB Audio Class Driver TOCTOU Race Condition

Publication date: 2026-09-08

Last updated on: 2026-09-24

Assigner: Microsoft Corporation

Description

Time-of-check time-of-use (toctou) race condition in Windows USB Audio Class driver (usbaudio.sys) allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-08

Last Modified

2026-09-24

Generated

2026-09-30

AI Q&A

2026-09-09

EPSS Evaluated

2026-09-27

NVD

CVE-2026-69859

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_usb_audio_class_driver	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-367	The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
CWE-191	The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

Attack-Flow Graph

Executive Summary

This is a time-of-check time-of-use (TOCTOU) race condition in the Windows USB Audio Class driver (usbaudio.sys). It allows an authorized attacker with local access to elevate their privileges by exploiting a timing issue in the driver's operations.

Impact Analysis

An attacker could exploit this to gain higher privileges on your system, potentially allowing them to install malicious software, access sensitive data, or perform unauthorized actions. Since it requires local access, physical or network access to the system is needed.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft to patch the usbaudio.sys driver. Disable USB audio devices if not required and monitor for unusual privilege escalation attempts.

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