CVE-2026-50430: Windows Push Notifications Info Disclosure

CVE-2026-50430 Overview

CVE-2026-50430 is an information disclosure vulnerability in the Windows Push Notifications component. An authorized attacker with local access can exploit the flaw to disclose sensitive information from the affected system. The weakness is categorized under [CWE-200], exposure of sensitive information to an unauthorized actor.

Microsoft published this issue on 2026-07-14 through the Microsoft Security Response Center (MSRC) update guide. Exploitation requires local access and low privileges, and it does not require user interaction. The vulnerability affects confidentiality only, without impacting integrity or availability.

Critical Impact
A local, authenticated attacker can read sensitive data handled by the Windows Push Notifications service, potentially exposing information belonging to other users or system components.

Affected Products

Microsoft Windows (Push Notifications component)
Refer to the Microsoft CVE-2026-50430 Update Guide for the authoritative list of affected builds
Systems that have not applied the latest Microsoft security update

Discovery Timeline

2026-07-14 - CVE-2026-50430 published to NVD
2026-07-15 - Last updated in NVD database

Technical Details for CVE-2026-50430

Vulnerability Analysis

The vulnerability resides in the Windows Push Notifications service, which handles asynchronous notification delivery to applications. The service manages notification payloads, subscription state, and per-user delivery contexts. A flaw in how the component isolates or scrubs data allows a local authenticated user to observe information that should remain protected.

The attack executes locally, so an adversary must already have valid credentials or an active session on the target. Successful exploitation results in confidentiality loss without altering system state or disrupting service availability. This aligns with the [CWE-200] classification for exposure of sensitive information to an unauthorized actor.

Because the flaw does not require user interaction, an attacker can automate exploitation through a background process running under a low-privileged account. The disclosed data may include notification content, tokens, or metadata associated with other users or higher-privileged contexts on the same host.

Root Cause

The root cause is improper access control or insufficient data segregation within the Windows Push Notifications component. Data that should be scoped to a specific security principal becomes readable across boundaries. Microsoft has not published the internal code paths involved. Consult the Microsoft CVE-2026-50430 Update Guide for authoritative technical details.

Attack Vector

The attack vector is local and requires low privileges. An attacker with an interactive or non-interactive session on the affected Windows host can interact with the Push Notifications service and retrieve data it processes. No user interaction is required, and no elevation of privilege is needed prior to the disclosure. Exploitation tooling has not been publicly reported, and the CVE is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified proof-of-concept code is publicly available. The vulnerability is described in prose based on the MSRC advisory. See the Microsoft advisory for technical details.

Detection Methods for CVE-2026-50430

Indicators of Compromise

Unexpected local processes accessing Windows Push Notification Service (WpnService) endpoints or the wpnprv.dll and wpnservice.dll libraries under unusual user contexts
Anomalous read operations against the notification database files stored under %LOCALAPPDATA%\Microsoft\Windows\Notifications\
Low-privileged user accounts enumerating notification subscriptions belonging to other principals

Detection Strategies

Baseline normal callers of the Push Notifications service and alert on unexpected process names, command lines, or parent-child chains touching notification APIs
Enable Windows event auditing on notification-related directories and monitor file access events for cross-user reads
Correlate local logon events with subsequent process activity that queries notification stores shortly after authentication

Monitoring Recommendations

Ingest Windows Security, Sysmon, and application event logs into a centralized analytics platform for cross-host correlation
Track patch state of the Windows Push Notifications component across the fleet and flag hosts that have not applied the July 2026 Microsoft update
Review EPSS telemetry periodically; the current EPSS probability is low, but any upward movement should trigger reprioritization

How to Mitigate CVE-2026-50430

Immediate Actions Required

Apply the Microsoft security update referenced in the Microsoft CVE-2026-50430 Update Guide to all affected Windows systems
Inventory hosts running the Windows Push Notifications service and prioritize multi-user systems such as terminal servers and shared workstations
Restrict interactive and remote logon rights on sensitive hosts to reduce the population of accounts that could exploit a local flaw

Patch Information

Microsoft addresses CVE-2026-50430 through its standard cumulative update channel. Administrators should deploy the update via Windows Update, Windows Server Update Services (WSUS), Microsoft Intune, or Microsoft Configuration Manager. Verify installation by checking the build number against the fixed version listed in the MSRC advisory. Reboot affected systems to complete patch application.

Workarounds

Limit local logon rights through Group Policy User Rights Assignment to reduce exposure until patching completes
Enforce least privilege on shared systems so that standard users cannot install background tooling that automates exploitation
Monitor for suspicious access patterns against notification storage paths as a compensating control where immediate patching is not feasible

bash

# Verify Windows build after patch installation
Get-ComputerInfo | Select-Object OsName, OsVersion, OsBuildNumber, WindowsVersion

# List installed security updates and confirm the July 2026 rollup is present
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20