UNKNOWN CISA KEV

CVE-2026-39987

CVSS v3

—

Unknown

EPSS Score

2.7 %

exploit probability

CISA KEV

Yes

known exploited

Exploitation

—

SSVC status

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 skipp

CISA Known Exploited Vulnerability

Date Added: 2026-04-23
Patch Due Date: 2026-05-07
Ransomware Use: Unknown

Technical details

Published: 2026-04-09

Frequently asked questions

What is CVE-2026-39987?

Is CVE-2026-39987 actively exploited?

Yes. CVE-2026-39987 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-05-07.

What is the CVSS score for CVE-2026-39987?

A CVSS score has not been assigned to CVE-2026-39987 yet.

Is CVE-2026-39987 affecting your environment?

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