CVE-2026-23744

CVE-2026-23744 RCE

While analyzing this vulnerability, I discovered that MCPJam Inspector exposed the /api/mcp/connect endpoint to the network by binding to 0.0.0.0. This endpoint accepts a JSON object containing serverConfig, including the fields command and args.

The application was intended to launch MCP servers, but it failed to properly validate user-supplied values before processing them. As a result, an attacker could send a crafted HTTP request containing arbitrary commands and arguments, which would then be executed by the server, leading to Remote Code Execution (RCE).

What I found most interesting was that the exploit payload was not arbitrary. By intercepting legitimate requests with Burp Suite, I observed that the application itself used the command and args fields. Understanding how these values flowed from an HTTP request into process creation helped me understand the root cause of the vulnerability rather than simply executing a public PoC.