CVE-2026-39987

9.8 CRITICAL CISA KEV - Actively Exploited
Published: April 09, 2026 Modified: April 23, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/marimo-team/marimo/pull/9098
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-39987
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
US Government Resource
https://www.sysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exploitation-in-under-10-hours
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Third Party Advisory

5 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
58.2%
98th percentile
Exploitation Status
Actively Exploited
Remediation due: 2026-05-07

Weaknesses (CWE)

Affected Vendors

coreweave