CVE-2026-39987
marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass
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 Vector Breakdown
AV:NAttack VectorAC:LAttack ComplexityPR:NPrivileges RequiredUI:NUser InteractionS:UScopeC:HConfidentialityI:HIntegrityA:HAvailabilityWeaknesses
Affected Products
Attack Graph
Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.
Exploitability
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
MITRE ATT&CK
2 techniquesReferences
Timeline
- Researchers Build Self-Replicating AI Worm That Operates Entirely on Local, Open-Weight Modelsen·The Hacker News· Summary only·
- Attackers Use LLM Agent for Post-Exploitation After Marimo CVE-2026-39987 Exploiten·The Hacker News· Summary only·
- 13th April – Threat Intelligence Reporten-us·Check Point Research·
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