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Marimo Notebook Flaw Could Run MCP Commands Before Cells Execute in Edit Mode

highnews

security

Source: The Hacker NewsAugust 25, 2026

Summary

Marimo, a notebook software, had a high-severity security flaw (CVE-2026-75149) that let attackers run malicious commands through a specially crafted notebook file when opened in edit mode, before any notebook cells executed. The vulnerability was a code injection issue (inserting harmful code into a program) affecting versions before 0.23.15 and rated 8.7-8.8 on the severity scale.

Solution / Mitigation

Update to Marimo version 0.23.15 or later. According to the source, "Marimo has addressed the issue in version 0.23.15" and "Users running an affected release should move to a version outside the affected range." The fix includes a PEP 723 hardening patch that treats notebook metadata as attacker-controlled and removes dangerous configuration sections (ai, mcp, completion, secrets, server) through an allowlist approach.