CVE-2026-41477: Deskflow Privilege Escalation Vulnerability

CVE-2026-41477 Overview

CVE-2026-41477 is a local privilege escalation vulnerability affecting Deskflow, a popular keyboard and mouse sharing application. The vulnerability exists in the Deskflow daemon which runs with SYSTEM-level privileges and exposes an IPC named pipe configured with WorldAccessOption enabled. This insecure configuration allows the daemon to process privileged commands without any form of authentication, enabling any local unprivileged user to execute arbitrary commands with SYSTEM privileges.

Critical Impact

Any local user can escalate privileges to SYSTEM by sending malicious commands through the unauthenticated IPC named pipe, potentially leading to complete system compromise.

Affected Products

• Deskflow stable version 1.20.0 and earlier
• Deskflow Continuous (prerelease) version 1.26.0.134 and earlier
• All Deskflow installations with the daemon running as SYSTEM

Discovery Timeline

• 2026-04-24 - CVE-2026-41477 published to NVD
• 2026-04-28 - Last updated in NVD database

Technical Details for CVE-2026-41477

Vulnerability Analysis

This vulnerability stems from a missing authentication for critical function (CWE-306) in the Deskflow daemon's IPC implementation. The daemon service operates with SYSTEM privileges to facilitate keyboard and mouse sharing functionality across systems. However, the named pipe used for inter-process communication is exposed with world-accessible permissions, creating a significant security gap.

When the Deskflow daemon initializes, it creates a named pipe for communication with the client application. The WorldAccessOption flag grants all local users read and write access to this pipe. Since the daemon processes commands received through this pipe without verifying the identity or privileges of the sender, any local process—regardless of its privilege level—can issue commands that will be executed with SYSTEM authority.

This design flaw represents a classic case of improper access control combined with excessive privilege, where the high-privilege daemon trusts all input from the locally accessible IPC channel.

Root Cause

The root cause of CVE-2026-41477 is the combination of two security misconfigurations:

1. Overly permissive named pipe ACL: The IPC named pipe is created with WorldAccessOption, granting all local users access to communicate with the daemon
2. Missing authentication checks: The daemon does not implement any authentication mechanism to verify that commands originate from authorized sources before processing them with elevated privileges

This architectural weakness violates the principle of least privilege by allowing unrestricted access to a privileged communication channel.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have some level of access to the target system. The exploitation path follows these steps:

1. An unprivileged local user identifies the Deskflow daemon's named pipe endpoint
2. The attacker connects to the named pipe, which accepts connections from any local user due to the WorldAccessOption configuration
3. The attacker crafts and sends malicious commands through the pipe
4. The daemon processes these commands without authentication verification
5. Commands execute with SYSTEM privileges, granting the attacker complete control over the system

For detailed technical information about the vulnerability mechanism and exploitation, refer to the GitHub Security Advisory.

Detection Methods for CVE-2026-41477

Indicators of Compromise

• Unusual processes spawning as child processes of the Deskflow daemon service
• Unexpected named pipe connections from non-standard user accounts to Deskflow IPC endpoints
• SYSTEM-level command execution originating from the Deskflow daemon context
• Anomalous privilege escalation events coinciding with Deskflow service activity

Detection Strategies

• Monitor Windows Security Event logs for suspicious process creation events (Event ID 4688) where the parent process is the Deskflow daemon
• Implement named pipe auditing to track connections to Deskflow IPC endpoints from unexpected user contexts
• Deploy endpoint detection rules to alert on privilege escalation patterns associated with the Deskflow daemon
• Use SentinelOne's behavioral AI to detect anomalous child process spawning from the Deskflow service

Monitoring Recommendations

• Enable Windows Security auditing for process creation with command line logging
• Configure alerting for any SYSTEM-level process execution originating from Deskflow daemon
• Implement file integrity monitoring on Deskflow installation directories
• Review system logs for unexpected service behavior or command execution patterns

How to Mitigate CVE-2026-41477

Immediate Actions Required

• Upgrade Deskflow to the latest patched version that addresses this vulnerability
• If immediate patching is not possible, consider temporarily disabling the Deskflow daemon service
• Restrict physical and remote access to systems running vulnerable Deskflow versions
• Audit systems for signs of exploitation and unauthorized privilege escalation

Patch Information

The Deskflow development team has acknowledged this vulnerability in their security advisory. Users should upgrade to versions newer than 1.20.0 (stable) or 1.26.0.134 (Continuous) that include proper authentication mechanisms for the IPC named pipe. Consult the Deskflow Security Advisory for the latest patch information and download links.

Workarounds

• Run the Deskflow daemon with reduced privileges if application functionality permits
• Implement Windows Firewall or host-based access controls to limit which users can interact with the Deskflow service
• Use application whitelisting to prevent unauthorized processes from connecting to the named pipe
• Consider deploying Deskflow only on systems with trusted user accounts until patching is complete

# Temporarily disable Deskflow daemon service until patching
sc stop DeskflowDaemon
sc config DeskflowDaemon start= disabled

# Verify service status
sc query DeskflowDaemon