CVE-2026-50403

Analyzed Analyzed - Analysis Complete

Race Condition in Windows Runtime Elevates Privileges

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 Runtime allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-14

Last Modified

2026-07-22

Generated

2026-08-04

AI Q&A

2026-07-14

EPSS Evaluated

2026-08-02

NVD

CVE-2026-50403

EUVD

EUVD-2026-43920

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_11_26h1	to 10.0.28000.2269 (exc)
microsoft	windows_server_2025	to 10.0.26100.33158 (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_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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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-2026-50403 is a race condition vulnerability in the Windows Runtime. 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 Runtime. This could enable the attacker to elevate their privileges on the affected system.

Detection Guidance

This vulnerability involves a race condition in Windows Runtime that could allow privilege escalation. Detection typically requires analyzing system logs for unusual privilege changes or monitoring for concurrent access to shared resources. Use Windows Event Viewer to check for Event ID 4672 (Special Privileges Assigned) or Event ID 4688 (New Process Created) for suspicious activity. No specific commands are provided in the available resources.

Impact Analysis

If exploited, this vulnerability could have the following impacts:

An attacker with local access to your system could gain elevated privileges, allowing them to perform actions they would not normally be authorized to do.
Elevated privileges could enable the attacker to install malicious software, modify system configurations, or access sensitive data that would otherwise be restricted.
The attacker could potentially take full control of the affected system, leading to further compromise of your network or data.

Compliance Impact

This vulnerability could impact compliance with common standards and regulations in the following ways:

GDPR: If the vulnerability leads to unauthorized access to personal data, it could result in a data breach. Under GDPR, organizations must protect personal data and report breaches within 72 hours. Failure to do so could lead to significant fines.
HIPAA: For organizations handling protected health information (PHI), this vulnerability could lead to unauthorized access or disclosure of PHI. HIPAA requires safeguards to protect PHI, and a breach could result in penalties and mandatory corrective actions.
Other standards (e.g., ISO 27001, NIST): The vulnerability could indicate a failure to implement proper access controls or secure coding practices, which are required by these frameworks. Exploitation could lead to non-compliance and potential audit failures.

Mitigation Strategies

Apply the latest security updates provided by Microsoft to address CVE-2026-50403. This vulnerability is mentioned in the Microsoft Update Guide, which typically includes patches or workarounds.

Check the Microsoft Security Response Center (MSRC) update guide for CVE-2026-50403 to download and install the relevant patch.
Ensure all systems running Windows Runtime are updated to the latest version to prevent exploitation.
Monitor Microsoft's official communications for any additional mitigation steps or advisories related to this vulnerability.

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