Vulnerability · Published Aug 4, 2026 · Assigned by VulnCheck

CVE-2026-67618marimo < 0.23.15 API Key Exfiltration via Malicious Notebook PEP-723 Metadata

Medium 6.5

In plain English

A medium-severity insufficient verification of data authenticity in marimo from marimo-team. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 77.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 products (as reported)

Vendor	Product	Versions
marimo-team	marimo	0 – before 0.23.15

Weakness: CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

References

Release Notes release-notes
Pull Request issue-tracking
Patch Commit patch
https://www.vulncheck.com/advisories/marimo-api-key-exfiltration-via-malicious-notebook-pep-723-metadata third-party-advisory