NotebookLM MCP is an MCP server and HTTP service for interacting with Google NotebookLM and exporting generated content to local vault directories. Versions 1.6.0 through 2.0.2 contain a path traversal vulnerability in the POST /batch-to-vault endpoint, also exposed through the batchtovault MCP tool beginning in version 1.7.0, because attacker-controlled vaultdir and slugprefix values can cause Markdown and JSON files to be written outside the intended vault directory to any location writable by the server process. Version 2.0.3 sanitizes slugprefix and supports vault containment when NOTEBOOKLMVAULTROOT is configured; containment is not enabled if that variable is unset. Users unable to upgrade should run the server as a dedicated unprivileged account restricted to the intended vault, keep the HTTP endpoint limited to localhost, and validate vaultdir values supplied by LLMs processing untrusted content.