CVE-2026-25186: Windows ATBroker Information Disclosure

CVE-2026-25186 Overview

CVE-2026-25186 is an Information Exposure vulnerability affecting the Windows Accessibility Infrastructure, specifically the ATBroker.exe component. This vulnerability allows an authorized local attacker to disclose sensitive information through improper handling of data within the accessibility framework. The flaw is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), indicating that the vulnerable component fails to properly restrict access to sensitive data that should remain protected.

Critical Impact
An authenticated local attacker can exploit this vulnerability to access sensitive information that could be leveraged for further attacks, credential theft, or reconnaissance within the affected Windows environment.

Affected Products

Windows Accessibility Infrastructure (ATBroker.exe)
Windows operating systems with Accessibility features enabled

Discovery Timeline

2026-03-10 - CVE-2026-25186 published to NVD
2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-25186

Vulnerability Analysis

This vulnerability resides in the Windows Accessibility Infrastructure, specifically within the ATBroker.exe executable. The Assistive Technology Broker (ATBroker) is a Windows component responsible for facilitating communication between assistive technology applications and the operating system's accessibility features.

The flaw enables an authorized attacker with local access to disclose sensitive information. The vulnerability requires low privileges and no user interaction to exploit, though it is limited to local attack scenarios. The impact is focused entirely on confidentiality, with high potential for information disclosure but no direct impact on system integrity or availability.

Root Cause

The root cause of CVE-2026-25186 is improper information handling within the Windows Accessibility Infrastructure. The ATBroker.exe component fails to adequately protect sensitive information from disclosure to local users who should not have access to that data. This represents a classic CWE-200 pattern where sensitive data is exposed through insufficient access controls or improper data handling mechanisms within the accessibility subsystem.

Attack Vector

The attack requires local access to the target system. An attacker who has already obtained authorized access to the Windows environment (even with low privileges) can exploit this vulnerability to extract sensitive information. The local attack vector combined with low complexity and no user interaction requirement means that exploitation is straightforward once an attacker has established a foothold on the target system.

The exploitation flow typically involves:

An attacker gains low-privileged local access to a Windows system
The attacker interacts with or monitors the ATBroker.exe accessibility component
Sensitive information is disclosed through the vulnerable handling mechanisms
The attacker can leverage this information for lateral movement or privilege escalation

Detection Methods for CVE-2026-25186

Indicators of Compromise

Unusual process activity or access patterns involving ATBroker.exe
Unexpected queries or interactions with the Windows Accessibility Infrastructure from non-accessibility applications
Anomalous data access or exfiltration attempts originating from accessibility-related processes

Detection Strategies

Monitor for suspicious process behavior involving ATBroker.exe and related accessibility components
Implement endpoint detection rules to flag unusual access patterns to accessibility infrastructure
Deploy behavioral analysis to detect information harvesting activities from low-privileged accounts
Configure Windows Event Logging to capture detailed accessibility subsystem events

Monitoring Recommendations

Enable enhanced logging for Windows Accessibility Infrastructure components
Implement file and registry integrity monitoring for accessibility-related resources
Deploy SentinelOne Singularity Platform for real-time behavioral detection of exploitation attempts
Establish baseline behavior profiles for ATBroker.exe to identify anomalous activity

How to Mitigate CVE-2026-25186

Immediate Actions Required

Apply the latest Microsoft security updates addressing CVE-2026-25186
Review and restrict accessibility feature usage on sensitive systems where not required
Implement least-privilege access controls to limit local user capabilities
Monitor systems for signs of exploitation while awaiting patch deployment

Patch Information

Microsoft has released a security update to address this vulnerability. Organizations should apply the patch available through the Microsoft Security Update Guide for CVE-2026-25186. The update should be deployed through standard Windows Update mechanisms or enterprise patch management solutions such as WSUS, SCCM, or Intune.

Workarounds

Disable unnecessary accessibility features on systems where they are not required for business operations
Implement application control policies to restrict unauthorized interactions with ATBroker.exe
Apply network segmentation to limit the exposure of potentially vulnerable systems
Consider temporarily restricting local access to sensitive systems until patching is complete

bash

# Verify Windows Update status for the security patch
Get-HotFix | Where-Object {$_.Description -like "*Security*"} | Sort-Object InstalledOn -Descending

# Check ATBroker.exe version to confirm patch application
Get-Item "C:\Windows\System32\ATBroker.exe" | Select-Object VersionInfo