CVE-2026-75149: Marimo Notebook MCP Code Injection Flaw
A high-severity code injection vulnerability (CVE-2026-75149) in Marimo notebook software allowed attackers to embed malicious Model Context Protocol (MCP) server commands in crafted notebooks, triggering local subprocess execution before any user cell runs. The flaw, scoring 8.8 on CVSS v3.1, required no attacker authentication and only needed the victim to open the notebook in edit mode. Marimo patched the issue in version 0.23.15 by treating all notebook metadata as attacker-controlled and enforcing an allowlist over configuration sections including AI, MCP, and secrets.