CVE-2026-54449

Name of the Vulnerable Software and Affected Versions LangBot versions prior to 4.10.8

Description Authenticated users can achieve arbitrary command execution on the server due to an inadequate authorization boundary when adding or modifying an STDIO MCP server configuration. In the file src/langbot/pkg/provider/tools/loaders/mcp.py, the StdioServerParameters function accepts configured commands and arguments to start a server-side subprocess. An attacker with a valid account can use the Extensions MCP configuration to execute commands with the privileges of the LangBot service, potentially leading to full system takeover, data disclosure, modification, and service disruption.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability. As a temporary workaround, restrict access to the Extensions MCP configuration to prevent unauthorized users from adding or modifying STDIO server parameters.