CVE-2026-0391: Microsoft Edge Android Spoofing Vulnerability

CVE-2026-0391 Overview

CVE-2026-0391 is a user interface misrepresentation vulnerability in Microsoft Edge for Android that allows an unauthorized attacker to perform spoofing attacks over a network. This vulnerability falls under CWE-451 (User Interface (UI) Misrepresentation of Critical Information), where the application fails to properly display security-critical information to users, potentially enabling phishing and social engineering attacks.

Critical Impact

Attackers can exploit this vulnerability to deceive users by misrepresenting critical UI elements, potentially leading to credential theft, malware installation, or unauthorized access to sensitive information through sophisticated spoofing attacks.

Affected Products

• Microsoft Edge for Android

Discovery Timeline

• 2026-02-05 - CVE-2026-0391 published to NVD
• 2026-02-05 - Last updated in NVD database

Technical Details for CVE-2026-0391

Vulnerability Analysis

This vulnerability affects the user interface rendering components of Microsoft Edge on Android devices. The flaw allows attackers to manipulate how critical security information is displayed to users, creating opportunities for sophisticated spoofing attacks. The vulnerability requires network access to exploit but does not require any privileges or user interaction, though the attack complexity is considered high.

The impact profile indicates that successful exploitation could lead to high confidentiality impact and low integrity impact, while availability remains unaffected. This suggests attackers could potentially access sensitive information or deceive users into taking actions they would not otherwise take.

Root Cause

The root cause stems from improper handling of user interface elements that display security-critical information in Microsoft Edge for Android. CWE-451 vulnerabilities occur when an application's UI fails to accurately convey the actual state of security-relevant operations or content, allowing malicious actors to present misleading information to users.

In the context of mobile browsers, this can manifest in several ways, including manipulated address bars, fake security indicators, or misrepresented content origins that could lead users to believe they are interacting with legitimate websites when they are actually on malicious pages.

Attack Vector

The attack vector is network-based, meaning an attacker can exploit this vulnerability remotely without requiring local access to the target device. The attack scenario typically involves:

1. An attacker sets up a malicious website or intercepts network traffic
2. The attacker crafts content that exploits the UI misrepresentation flaw
3. When a victim accesses the content through Microsoft Edge for Android, the browser displays misleading security information
4. The victim, trusting the false UI indicators, may proceed with actions they would otherwise avoid, such as entering credentials or downloading content

The high attack complexity indicates that successful exploitation requires specific conditions or additional preparation by the attacker, making mass exploitation less likely but targeted attacks still feasible.

Detection Methods for CVE-2026-0391

Indicators of Compromise

• Unusual browser behavior where URL bar or security indicators display inconsistent information
• Reports from users of unexpected certificate warnings followed by apparent resolution
• Network traffic patterns indicating redirection or man-in-the-middle activity targeting mobile devices
• Phishing complaints from users who believed they were on legitimate sites

Detection Strategies

• Monitor for anomalous network traffic patterns associated with spoofing attacks targeting mobile browsers
• Implement network security monitoring to detect potential man-in-the-middle attacks
• Review endpoint detection logs for suspicious browser activity on Android devices
• Deploy URL filtering and reputation services to identify potential malicious domains

Monitoring Recommendations

• Enable enhanced logging for mobile device management (MDM) solutions to track browser security events
• Monitor for user reports of suspicious browser behavior that could indicate exploitation attempts
• Track Microsoft Edge for Android version deployments across your environment to ensure patch compliance
• Implement network traffic analysis to identify potential spoofing attack patterns

How to Mitigate CVE-2026-0391

Immediate Actions Required

• Update Microsoft Edge for Android to the latest patched version as soon as available
• Educate users about the risks of spoofing attacks and the importance of verifying website authenticity through multiple indicators
• Consider implementing additional network security controls such as DNS filtering and secure web gateways
• Enable Mobile Threat Defense solutions to detect potential exploitation attempts

Patch Information

Microsoft has acknowledged this vulnerability and provides detailed information through their official security advisory. Organizations should consult the Microsoft CVE-2026-0391 Advisory for specific patch information, affected version details, and remediation guidance.

The patch should be deployed through standard mobile application update channels. Organizations using mobile device management (MDM) solutions should push the updated Edge browser version to managed Android devices.

Workarounds

• Advise users to always verify website URLs manually and look for HTTPS indicators before entering sensitive information
• Consider using alternative browsers on Android until the patch is applied
• Implement network-level protections such as DNS filtering and web proxies to reduce exposure to malicious sites
• Enable phishing protection features in endpoint security solutions

# Android ADB command to check Microsoft Edge version
adb shell dumpsys package com.microsoft.emmx | grep versionName

# Force update check through Play Store
adb shell am start -a android.intent.action.VIEW -d 'market://details?id=com.microsoft.emmx'