CVE-2026-62734

Analyzed Analyzed - Analysis Complete

Race Condition in Windows Telephony Service Elevates Privileges

Publication date: 2026-08-11

Last updated on: 2026-08-18

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

2026-08-11

Last Modified

2026-08-18

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-62734

EUVD

EUVD-2026-56647

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_server_2016	to 10.0.14393.9418 (exc)
microsoft	windows_server_2022	to 10.0.20348.5440 (exc)
microsoft	windows_server_2025	to 10.0.26100.33222 (exc)
microsoft	windows_10_1809	to 10.0.17763.9121 (exc)
microsoft	windows_10_1809	to 10.0.17763.9121 (exc)
microsoft	windows_server_2019	to 10.0.17763.9121 (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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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

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

Detection Guidance

Detection of this race condition vulnerability in Windows Telephony Service requires monitoring for unusual privilege escalation events or race condition indicators in system logs. Check for repeated failed privilege escalation attempts or unexpected service behavior. Use Windows Event Viewer to inspect Security and System logs for anomalies related to the Telephony service.

Impact Analysis

An attacker could exploit this to gain higher system privileges than intended, 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 through a race condition in Windows Telephony Service, which could enable unauthorized access to sensitive system resources. For compliance standards like GDPR or HIPAA, such unauthorized access risks data breaches or unauthorized processing of personal or health information, potentially violating confidentiality and integrity requirements.

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the Windows Telephony Service. Monitor Microsoft's security advisories for patches and follow their recommended mitigation steps.

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