marimo vulnerability

marimo before 0.23.15 contains a configuration injection vulnerability that allows notebook authors to exfiltrate operator API keys by embedding a malicious base_url in PEP-723 inline script metadata, which is merged into session configuration with higher precedence than the operator's own settings due to insufficient sanitization in sanitize_pyproject_dict. When an operator opens the crafted notebook and makes an AI request, marimo resolves the attacker-controlled base_url from the notebook config while falling back to the operator's OPENAI_API_KEY environment variable for authentication, transmitting the API key to the attacker-controlled endpoint without requiring any cell execution.

Published 4 Aug 2026Updated 16 Sep 20264 sources
CVSS 7.1

What happened

marimo before 0.23.15 contains a configuration injection vulnerability that allows notebook authors to exfiltrate operator API keys by embedding a malicious base_url in PEP-723 inline script metadata, which is merged into session configuration with higher precedence than the operator's own settings due to insufficient sanitization in sanitize_pyproject_dict. When an operator opens the crafted notebook and makes an AI request, marimo resolves the attacker-controlled base_url from the notebook config while falling back to the operator's OPENAI_API_KEY environment variable for authentication, transmitting the API key to the attacker-controlled endpoint without requiring any cell execution.

Affected versions

marimo: before 0.23.15 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.