CVE-2025-50155 Overview
CVE-2025-50155 is a type confusion vulnerability in the Windows Push Notifications component. An authorized local attacker can exploit the flaw to elevate privileges on affected systems. The issue is tracked under CWE-122 and affects a wide range of Windows client and server releases, from Windows 10 1507 through Windows Server 2025. Microsoft published the advisory on August 12, 2025, and rates the flaw as High severity. Successful exploitation yields high impact to confidentiality, integrity, and availability on the local host.
Critical Impact
A local, authenticated attacker can gain elevated privileges on the affected Windows system by triggering type confusion in the Push Notifications service.
Affected Products
- Microsoft Windows 10 (1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (22H2, 23H2, 24H2)
- Microsoft Windows Server 2012, 2016, 2019, 2022, 2022 23H2, and 2025
Discovery Timeline
- 2025-08-12 - Microsoft releases security update addressing CVE-2025-50155
- 2025-08-12 - CVE-2025-50155 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-50155
Vulnerability Analysis
The vulnerability resides in the Windows Push Notifications service, which relays and processes toast and system notifications for local applications. The service accesses a resource using an incompatible type, a class of memory-safety defect known as type confusion. When the service interprets a memory region as one object type while it actually holds another, method dispatch and field access operate on attacker-influenced data. This can be leveraged to corrupt memory managed by a higher-privileged process. Because the Push Notifications service runs with elevated rights, a successful attacker inherits those privileges. The advisory maps the flaw to CWE-122, indicating heap-based corruption as the exploitation surface.
Root Cause
The root cause is missing or inadequate validation of an object's actual type before the Push Notifications component performs operations that assume a specific layout. When the incoming object differs from the expected type, subsequent reads or writes operate on incorrect fields. Adjacent heap structures then become writable through the confused type's methods, enabling controlled memory corruption.
Attack Vector
Exploitation requires local access and low-privileged authentication on the target host. The attacker submits crafted input to the Push Notifications interface, triggering the type confusion during message processing. No user interaction is required. After corruption, the attacker pivots to code execution in the context of the elevated service, obtaining SYSTEM-level privileges suitable for persistence, credential theft, or lateral movement. Refer to the Microsoft Security Update CVE-2025-50155 advisory for vendor technical details.
Detection Methods for CVE-2025-50155
Indicators of Compromise
- Unexpected crashes or restarts of the Windows Push Notification User Service (WpnUserService) or WpnService.
- New processes spawned by svchost.exe hosting WpnService running with SYSTEM privileges outside routine notification workflows.
- Anomalous child processes such as cmd.exe, powershell.exe, or rundll32.exe originating from Push Notification service host processes.
Detection Strategies
- Alert on process creation events (Windows Event ID 4688 or Sysmon Event ID 1) where the parent process is a svchost.exe instance hosting WpnService and the child is an interactive shell or scripting engine.
- Monitor Application and System event logs for repeated crash reports (Event ID 1000/1001) referencing Push Notification service binaries.
- Correlate low-privileged user sessions with sudden appearance of SYSTEM-context processes on the same host.
Monitoring Recommendations
- Enable Sysmon with process creation, image load, and process access logging to capture exploitation attempts against WpnService.
- Forward endpoint telemetry to a centralized analytics platform to baseline normal Push Notification service behavior and flag deviations.
- Track patch compliance across all Windows client and server SKUs listed in the Microsoft advisory.
How to Mitigate CVE-2025-50155
Immediate Actions Required
- Apply the August 2025 Microsoft security updates to every affected Windows 10, Windows 11, and Windows Server build without delay.
- Prioritize patching multi-user systems, jump hosts, and terminal servers where local authenticated users are most likely to attempt privilege escalation.
- Audit local account membership and remove unnecessary interactive logon rights to reduce the pool of potential attackers.
Patch Information
Microsoft has released cumulative security updates that remediate CVE-2025-50155 across all supported Windows client and server versions. Administrators should consult the Microsoft Security Update Guide for CVE-2025-50155 to identify the specific KB article and build number applicable to each deployed image.
Workarounds
- No official workaround has been published by Microsoft; applying the security update is the required remediation.
- As a compensating control, restrict interactive and remote desktop logon to trusted administrators until patches are deployed.
- Enforce application allowlisting to block unauthorized binaries that could stage the exploit against the Push Notifications service.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
