CVE-2026-79748 in MCPHub
Summary
by MITRE • 08/31/2026
MCPHub is a unified hub for centrally managing and dynamically orchestrating multiple MCP servers/APIs into separate endpoints with flexible routing strategies. Prior to version 0.12.15, the POST /api/servers and PUT /api/servers/:name endpoints in MCPHub create/update MCP server configurations and then immediately spawn the configured stdio process via child_process.spawn. Authentication is required, but there is no authorization check restricting these endpoints to admins, and there is no allowlist/sanitization on the command and args fields. As a result, any authenticated non-admin user can submit a server configuration with command:"/bin/sh" (or any other binary) and arbitrary args, causing MCPHub to execute the attacker-controlled process as the MCPHub server's OS user (commonly root in the published Docker image and in npx/systemd deployments). This issue has been patched in version 0.12.15.
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Analysis
by VulDB Data Team • 08/31/2026
The vulnerability identified in MCPHub prior to version 0.12.15 represents a critical combination of broken access control and command injection flaws that allow authenticated users to achieve remote code execution with the privileges of the underlying server process. MCPHub functions as a unified hub for centrally managing and dynamically orchestrating multiple Model Context Protocol servers, allowing administrators to define configurations that are then executed via standard input/output processes. The core technical flaw lies in the implementation of the POST /api/servers and PUT /api/servers/:name endpoints, which accept user-supplied data to configure these server instances. While authentication is enforced for access to these API routes, there is a complete absence of authorization checks to verify if the authenticated user holds administrative privileges required to modify system-level configurations. This lack of role-based access control means that any valid credential set can interact with endpoints intended exclusively for privileged operators.
Beyond the authorization failure, the application exhibits severe input validation deficiencies regarding the command and arguments fields within the server configuration payload. The software directly passes these unsanitized inputs into a child_process.spawn call without implementing an allowlist of permitted binaries or performing adequate sanitization to prevent shell metacharacter interpretation or argument injection. This design choice effectively creates a direct path for arbitrary command execution. An attacker can construct a malicious request specifying the command field as /bin/sh, along with carefully crafted arguments that invoke system commands such as id, whoami, or more destructive payloads like downloading and executing reverse shells. Because MCPHub typically runs within environments where it requires broad filesystem access to manage server configurations, this process often executes under high-privilege accounts, frequently root in published Docker images or systemd deployments, thereby granting the attacker full control over the host operating system.
The operational impact of this vulnerability is severe, as it allows for complete compromise of the infrastructure hosting MCPHub. An authenticated non-admin user can escalate their privileges from a standard application account to that of the root user by exploiting the misconfigured spawn mechanism. This leads to potential data exfiltration, lateral movement within the network, installation of persistent backdoors, and disruption of service availability. The vulnerability aligns with CWE-269 Improper Privilege Management due to the failure to enforce role-based restrictions on sensitive administrative functions, as well as CWE-78 OS Command Injection resulting from the unsafe handling of user-supplied input in system commands. From a tactical perspective, this exploitation technique corresponds to ATT&CK techniques T1059 Command and Scripting Interpreter for executing arbitrary code and potentially T1068 Exploitation for Privilege Escalation if the attacker leverages the root access gained through the spawn process to further compromise other systems or data.
Mitigation strategies must address both the architectural design flaws and immediate configuration issues. The primary remediation is upgrading MCPHub to version 0.12.15 or later, where these vulnerabilities have been patched by implementing proper authorization checks and input validation mechanisms. For environments that cannot immediately upgrade, administrators should enforce strict network-level access controls to restrict API endpoint availability only to trusted administrative clients if possible, although this is less effective than fixing the application logic. Additionally, running MCPHub with minimal necessary privileges using non-root users in containerized or systemd deployments can significantly reduce the blast radius of such an exploit. Implementing a Web Application Firewall ruleset that detects and blocks common command injection patterns in POST bodies may provide temporary defense-in-depth, but it is not a substitute for fixing the underlying code vulnerabilities. Regular security audits focusing on authentication flows and input sanitization practices are essential to prevent similar issues in future development cycles.