CVE-2026-50669

Analyzed Analyzed - Analysis Complete

Race Condition in Windows Telephony Service Allows Privilege Escalation

Publication date: 2026-07-14

Last updated on: 2026-07-22

Assigner: Microsoft Corporation

Description

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

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-14

Last Modified

2026-07-22

Generated

2026-08-04

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-50669

EUVD

EUVD-2026-44126

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9339 (exc)
microsoft	windows_10_1607	to 10.0.14393.9339 (exc)
microsoft	windows_10_1809	to 10.0.17763.9020 (exc)
microsoft	windows_10_1809	to 10.0.17763.9020 (exc)
microsoft	windows_server_2016	to 10.0.14393.9339 (exc)
microsoft	windows_server_2019	to 10.0.17763.9020 (exc)
microsoft	windows_server_2022	to 10.0.20348.5386 (exc)
microsoft	windows_server_2025	to 10.0.26100.33158 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2525 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2525 (exc)
microsoft	windows_11_24h2	to 10.0.26100.8875 (exc)
microsoft	windows_11_24h2	to 10.0.26100.8875 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7548 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7548 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7548 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7548 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7548 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7548 (exc)
microsoft	windows_11_25h2	to 10.0.26200.8875 (exc)
microsoft	windows_11_25h2	to 10.0.26200.8875 (exc)

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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

CVE-2026-50669 is a race condition vulnerability in the Windows Telephony Service. A race condition occurs when multiple processes or threads access a shared resource without proper synchronization, leading to unpredictable behavior.

In this case, the vulnerability allows an authorized attacker with local access to exploit the improper synchronization in the Windows Telephony Service. By doing so, the attacker can elevate their privileges on the system, gaining higher-level permissions than originally granted.

Impact Analysis

If you are affected by this vulnerability, an attacker with local access to your system could exploit it to elevate their privileges. This means they could gain administrative or system-level access, allowing them to:

Execute arbitrary code with higher privileges.
Install or uninstall software without your knowledge.
Access, modify, or delete sensitive data stored on the system.
Disable security mechanisms, making the system more vulnerable to further attacks.

The impact is particularly severe in environments where multiple users share a system or where the system handles sensitive operations.

Compliance Impact

This vulnerability can have significant implications for compliance with standards and regulations, depending on the context of the affected system:

GDPR (General Data Protection Regulation): If the system processes personal data of EU citizens, an attacker exploiting this vulnerability could gain unauthorized access to that data. This could lead to a data breach, triggering GDPR's reporting requirements and potential fines for failing to protect personal data adequately.
HIPAA (Health Insurance Portability and Accountability Act): In healthcare environments, if the system stores or processes protected health information (PHI), this vulnerability could result in unauthorized access to PHI. This would constitute a breach under HIPAA, requiring notification and potentially leading to penalties for non-compliance.
Other standards (e.g., ISO 27001, NIST): Many compliance frameworks require organizations to maintain the integrity, confidentiality, and availability of systems and data. A privilege escalation vulnerability like this undermines these principles, potentially leading to non-compliance if not addressed promptly.

Organizations should assess whether this vulnerability affects systems within their compliance scope and take appropriate remediation steps to avoid regulatory risks.

Mitigation Strategies

Apply the security update provided by Microsoft to address the race condition in the Windows Telephony Service.

Ensure that only trusted users with limited privileges have access to the affected system until the patch is applied.

Monitor the Microsoft Security Response Center (MSRC) for official guidance and updates related to CVE-2026-50669.

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