CVE-2026-107824 in x64dbg-mcp-server
Summary
by MITRE • 10/09/2026
x64dbg-MCP Server is a native Model Context Protocol (MCP) plugin for x64dbg that exposes the debugger's full functionality over HTTP. Prior to 1.1, x64dbg-MCP Server exposes all MCP debugger tools over HTTP and SSE without authentication while listening on 0.0.0.0 by default. Any unauthenticated network client that can reach the default port, 9094 for x64 or 9095 for x32, can execute arbitrary x64dbg commands, attach to processes by PID, read and write debuggee memory, and write files to arbitrary paths. This issue is fixed in version 1.1.
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Analysis
by VulDB Data Team • 10/09/2026
The vulnerability identified involves the x64dbg-MCP Server, a native Model Context Protocol plugin designed for the x64dbg debugger that exposes debugging functionalities over HTTP and Server-Sent Events. Prior to version 1.1, this service was configured with critical security misconfigurations that fundamentally compromised the integrity of the host system it operated on. The primary flaw lies in the default binding address being set to 0.0.0.0, which causes the server to listen for incoming connections on all available network interfaces rather than restricting access to localhost or a specific internal interface. This configuration effectively exposes the debugging capabilities directly to any network segment where the host resides, making them accessible to remote attackers who can reach the default ports, specifically 9094 for x64 processes and 9095 for x32 processes.
The absence of authentication mechanisms represents a severe authorization failure within the application architecture. By exposing all MCP debugger tools without requiring any form of credential verification or session management, the service allows any unauthenticated network client to interact with the debugging engine as if they were a local user with full privileges. This lack of access control enables an attacker who gains network connectivity to execute arbitrary x64dbg commands remotely. The operational impact is profound, as it grants the ability to attach to running processes by their process identifier without restriction. Once attached, the attacker can read and write memory contents from any debuggee process, effectively bypassing standard operating system protections that typically isolate application memory spaces.
Furthermore, the vulnerability extends beyond mere data exfiltration or manipulation of in-memory states. The exposed functionality allows for writing files to arbitrary paths on the file system through the debugger interface. This capability transforms a debugging tool into a potential remote code execution vector or a mechanism for persistent compromise, as an attacker could overwrite critical system binaries, inject malicious payloads via memory modification followed by process resumption, or exfiltrate sensitive data stored in application memory. The combination of network accessibility, lack of authentication, and high-privilege operations creates a scenario where the confidentiality, integrity, and availability of the host system are severely jeopardized.
This vulnerability aligns with CWE-287, which describes Improper Authentication, as well as CWE-434, Unrestricted Upload of File with Dangerous Type, given the file writing capabilities. In terms of offensive security frameworks, this behavior maps to MITRE ATT&CK technique T1055, Process Injection, and T1005, Data from Local System, due to the ability to manipulate process memory and read sensitive information remotely. The exploitation path is straightforward for any actor with network access, requiring no prior foothold on the machine other than connectivity to the exposed ports.
The issue has been addressed in version 1.1 of x64dbg-MCP Server through architectural changes that likely include binding to localhost by default or implementing strict authentication requirements before exposing sensitive debugging tools over HTTP and SSE protocols. To mitigate this risk for users operating older versions, it is imperative to restrict network access to the specific ports used by the service using firewall rules if upgrading is not immediately feasible. Additionally, administrators should audit their network configurations to ensure that development and debugging services are never exposed on public-facing interfaces or untrusted networks without robust authentication and encryption layers in place.