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CVE-2026-39987

CriticalCVSS 9.3 / 10
Published Apr 9, 2026·Last modified Jul 8, 2026
Affected Components(0)

No affected components available

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.

Risk Scores
Base Score
9.3

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
9.3

Active exploitation in the wild has been confirmed. Immediate patching or mitigation is required.

EPSS
95.34%

The exploit probability is critical. The vulnerability is very likely to be exploited in the next 30 days.

Exploit
Attacked

This vulnerability is actively being exploited in the wild. Please take immediate action to mitigate the risk.

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