VULNERABILITY INTELLIGENCE

CVE-2026-39987

CVSS score9.8 CRITICAL

EPSS probability99.56%

CISA KEVKnown exploited vulnerability

Published2026-04-09

Last modified2026-06-17

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Known Exploited Vulnerability

Marimo Remote Code Execution Vulnerability

Vendor / product: Marimo / Marimo

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.

Weakness classification

security-advisories@github.com: CWE-306

Primary references

security-advisories@github.com — Patch
security-advisories@github.com — Issue Tracking, Patch
security-advisories@github.com — Exploit, Mitigation, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0 — US Government Resource
134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Third Party Advisory