Marimo Pre-Auth RCE (CVE-2026-39987)
Date: 2026-04
Affected: Marimo Pre-Auth RCE (CVE-2026-39987)
Attack vector: rce
Category: real-world
Severity: Critical
CVE: CVE-2026-39987

CVSS 9.3. Marimo Python reactive notebook (~19.6k GitHub stars) terminal WebSocket endpoint `/terminal/ws` lacks authentication. Single WebSocket connection grants full PTY shell. Commonly runs as root in Docker. Sysdig honeypots observed exploitation within hours of disclosure. Confirmed exploited in the wild. Fixed in v0.23.0.


Mitigations:

Architectural layers (MAESTRO):