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

> Attackers can exfiltrate operator API keys by embedding malicious metadata in notebooks, causing keys to be sent to attacker-controlled endpoints.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 4 Aug 2026
- **Also known as:** GHSA-v9v8-jp27-55gf

## What is CVE-2026-67618?

CVE-2026-67618 is a high-severity vulnerability in marimo-team marimo, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### 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.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2026-67618?


## How do I fix CVE-2026-67618?

No fix has been published for CVE-2026-67618 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-67618 being exploited?

There is no known exploitation of CVE-2026-67618 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-67618 and fix it if it is affected.

What it is: CVE-2026-67618 is a high-severity vulnerability in marimo-team marimo, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-67618 in the wild and no public exploit code.

Affected product: marimo-team marimo. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-67618/ (Markdown: https://insights.sbomify.com/CVE-2026-67618/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67618
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67618
- OSV: https://osv.dev/vulnerability/CVE-2026-67618

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67618/
Summaries are generated and may contain mistakes; the official description above is the record.