CVE-2026-50450: Windows WWAN Service Race Condition Flaw

CVE-2026-50450 Overview

CVE-2026-50450 is a race condition vulnerability in the Windows Wireless Wide Area Network (WWAN) Service. The flaw stems from concurrent execution using a shared resource with improper synchronization [CWE-362]. An authorized local attacker can exploit the timing window to elevate privileges on an affected Windows system. Microsoft published the advisory on July 14, 2026.

The vulnerability requires local access and low privileges but no user interaction. Successful exploitation grants attackers elevated privileges with a scope change, meaning the impact extends beyond the initially vulnerable component. The attack complexity is high due to the precise timing required to win the race condition.

Critical Impact
A local, authenticated attacker who wins the race condition can achieve privilege escalation with high impact to confidentiality, integrity, and availability across security boundaries.

Affected Products

Microsoft Windows operating systems with the Wireless WAN Service enabled
Systems using cellular or mobile broadband connectivity components
Refer to the Microsoft CVE-2026-50450 Advisory for the full list of affected Windows builds

Discovery Timeline

2026-07-14 - CVE-2026-50450 published to NVD
2026-07-15 - Last updated in NVD database

Technical Details for CVE-2026-50450

Vulnerability Analysis

The Windows Wireless WAN Service manages cellular data connections and mobile broadband adapters. The service runs with elevated privileges and interacts with hardware, drivers, and user-mode components. The vulnerability arises when multiple threads access a shared resource without proper synchronization primitives such as mutexes or critical sections.

An attacker with local access and low privileges can trigger concurrent operations that reach the vulnerable code path. When the timing aligns, the attacker manipulates the shared resource between the check and the use, allowing unauthorized state changes. The scope change indicated by the CVSS metric shows that exploitation crosses a trust boundary, granting privileges to resources outside the originally compromised component.

Root Cause

The root cause is improper synchronization of shared resources within the WWAN Service. Race conditions [CWE-362] occur when the correctness of a computation depends on the relative timing of concurrent operations. Without proper locking, an attacker can interleave operations to place the service into an unintended state that bypasses security checks.

Attack Vector

Exploitation requires local access to the target system and low-level authenticated privileges. The attacker executes code that repeatedly triggers WWAN Service operations while simultaneously manipulating a shared resource. The high attack complexity reflects the need to reliably win the race window, which typically requires multiple attempts. No user interaction is required. Refer to the Microsoft CVE-2026-50450 Advisory for technical specifics.

Detection Methods for CVE-2026-50450

Indicators of Compromise

Unexpected child processes spawned by the Windows WWAN Service (WwanSvc) running with elevated privileges
Anomalous thread creation patterns targeting WWAN Service memory regions
Unusual local privilege escalations following interaction with mobile broadband components

Detection Strategies

Monitor process lineage for svchost.exe instances hosting WwanSvc for unexpected child processes or privilege transitions
Alert on repeated, rapid API calls to WWAN Service endpoints from non-administrative user contexts, which may indicate race condition exploitation attempts
Correlate local logon events with sudden privilege escalations on endpoints that expose cellular connectivity features

Monitoring Recommendations

Enable Windows security event logging for privilege assignment events (Event IDs 4672, 4673, 4674)
Deploy endpoint detection and response tooling that captures process, thread, and token manipulation telemetry
Baseline normal WWAN Service behavior and alert on deviations, particularly on laptops and mobile workstations

How to Mitigate CVE-2026-50450

Immediate Actions Required

Apply the Microsoft security update referenced in the Microsoft CVE-2026-50450 Advisory as soon as testing completes
Prioritize patching on laptops, tablets, and mobile workstations that use cellular connectivity
Restrict local logon rights and enforce least-privilege policies for standard users

Patch Information

Microsoft released a security update addressing CVE-2026-50450. Administrators should consult the Microsoft Security Response Center advisory for the specific KB article, affected builds, and deployment guidance through Windows Update, WSUS, or Microsoft Update Catalog.

Workarounds

Disable the Windows Wireless WAN Service (WwanSvc) on systems that do not require cellular or mobile broadband connectivity
Apply application control policies to restrict which processes standard users can launch on affected endpoints
Limit interactive local access to trusted administrators until patches are deployed

bash

# Disable the Wireless WAN Service on systems that do not need it
sc.exe config WwanSvc start= disabled
sc.exe stop WwanSvc