CVE-2026-4749: Miraclecast Security Vulnerability

CVE-2026-4749 Overview

CVE-2026-4749 is an information disclosure vulnerability affecting Miraclecast, an open-source implementation of WiFi Display (Miracast) for Linux. This vulnerability allows an attacker on the same adjacent network to potentially access sensitive information without requiring authentication or user interaction.

Critical Impact

Attackers within adjacent network proximity can exploit this vulnerability to gain unauthorized access to high-confidentiality data without any authentication requirements.

Affected Products

• Miraclecast versions prior to v1.0

Discovery Timeline

• 2026-03-24 - CVE-2026-4749 published to NVD
• 2026-03-24 - Last updated in NVD database

Technical Details for CVE-2026-4749

Vulnerability Analysis

This vulnerability in Miraclecast allows unauthorized information disclosure to attackers positioned on an adjacent network segment. The attack requires no special privileges and can be executed without any user interaction, making it a particularly accessible vulnerability for network-adjacent threat actors.

The nature of the vulnerability allows complete compromise of confidentiality for affected systems, while integrity and availability remain unaffected. This pattern suggests the vulnerability enables read-only unauthorized access to sensitive data rather than allowing modification or disruption of services.

Root Cause

The specific root cause has not been fully disclosed in the CVE information (classified as NVD-CWE-noinfo). Based on the available technical references, the issue was addressed through a pull request on the Miraclecast GitHub repository. The vulnerability appears to stem from improper handling of data within the Miracast protocol implementation, allowing adjacent network attackers to access information they should not have visibility into.

Attack Vector

The attack vector requires the adversary to be on an adjacent network (such as the same WiFi network or local network segment). The attack has low complexity and requires neither authentication nor user interaction. This makes the vulnerability exploitable in scenarios such as:

• Public WiFi networks where attackers can join the same network as potential victims
• Corporate environments where an attacker has gained access to the local network
• Home networks where an attacker is within wireless range

The vulnerability mechanism involves the Miracast WiFi Display protocol implementation. Attackers positioned on the adjacent network can potentially intercept or access sensitive data transmitted or processed by the Miraclecast service. For detailed technical analysis, refer to the GitHub pull request #555 which contains the remediation code.

Detection Methods for CVE-2026-4749

Indicators of Compromise

• Unusual network traffic patterns on the local network segment involving Miracast protocol communications
• Unexpected connections to the Miraclecast service from unknown adjacent network devices
• Anomalous data access patterns or information requests from non-authenticated sources

Detection Strategies

• Monitor network traffic for suspicious Miracast protocol activity, particularly from unauthorized devices on the adjacent network
• Implement network segmentation monitoring to detect lateral movement attempts targeting Miraclecast services
• Deploy endpoint detection solutions to identify exploitation attempts targeting Miraclecast processes

Monitoring Recommendations

• Enable verbose logging for Miraclecast services to capture connection attempts and data access events
• Configure network intrusion detection systems (IDS) to alert on anomalous WiFi Display protocol traffic
• Implement network access control (NAC) policies to restrict which devices can communicate with Miraclecast services

How to Mitigate CVE-2026-4749

Immediate Actions Required

• Update Miraclecast to version v1.0 or later immediately
• If immediate patching is not possible, consider disabling the Miraclecast service until the update can be applied
• Review network segmentation to limit exposure of systems running Miraclecast to untrusted adjacent network devices
• Audit systems for any signs of exploitation or unauthorized data access

Patch Information

The vulnerability has been addressed in Miraclecast version v1.0 and later. The fix is available through the official Miraclecast repository. System administrators should update to v1.0 or the latest available version. The remediation details can be found in the GitHub pull request #555.

Workarounds

• Disable Miraclecast services on systems where WiFi Display functionality is not required
• Implement strict network segmentation to isolate systems running Miraclecast from untrusted network segments
• Use network access control (NAC) to restrict which devices can connect to the same network segment as Miraclecast-enabled systems
• Consider using a dedicated, isolated network for Miracast functionality if the feature is business-critical

# Disable Miraclecast service temporarily until patched
sudo systemctl stop miraclecast
sudo systemctl disable miraclecast

# Verify service is stopped
systemctl status miraclecast