High · published August 19, 2026
marimo before 0.23.15 contains a code injection vulnerability in the notebook configuration handler that allows attackers to execute arbitrary commands by supplying a crafted MCP server entry with an attacker-controlled command value embedded in a notebook. When the notebook is opened in edit mode, marimo launches the specified command as a local subprocess before any notebook cell is executed, requiring no authentication or cell execution to trigger the vulnerability.