Vulnerability Description
marimo is a reactive Python notebook. Prior to 0.23.0, Marimo has a Pre-Auth RCE vulnerability. The terminal WebSocket endpoint /terminal/ws lacks authentication validation, allowing an unauthenticated attacker to obtain a full PTY shell and execute arbitrary system commands. Unlike other WebSocket endpoints (e.g., /ws) that correctly call validate_auth() for authentication, the /terminal/ws endpoint only checks the running mode and platform support before accepting connections, completely skipping authentication verification. This vulnerability is fixed in 0.23.0.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Coreweave | Marimo | < 0.23.0 |
Related Weaknesses (CWE)
References
- https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cPatch
- https://github.com/marimo-team/marimo/pull/9098Issue TrackingPatch
- https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xcExploitMitigationVendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-US Government Resource
- https://www.sysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exExploitThird Party Advisory
FAQ
What is CVE-2026-39987?
CVE-2026-39987 is a vulnerability with a CVSS score of 9.8 (CRITICAL). marimo is a reactive Python notebook. Prior to 0.23.0, Marimo has a Pre-Auth RCE vulnerability. The terminal WebSocket endpoint /terminal/ws lacks authentication validation, allowing an unauthenticate...
How severe is CVE-2026-39987?
CVE-2026-39987 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-39987?
Check the references section above for vendor advisories and patch information. Affected products include: Coreweave Marimo.