Vulnerability Analysis
marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass
CVE-2026-39987
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.
CISA KEV
Nuclei Template
CVSS Base Score
9.3
CRITICAL
Exploitability:-
Impact Score:-
Temporal Score:-
EPSS:95.64%
Threat Intelligence Signals
CISA KEV
YES
KEV Date Added
2026-04-23
Ransomware Use
Unknown
KEV Due Date
2026-05-07
VulnCheck In-the-Wild
No
Nuclei Template
YES
EPSS Score
95.645%
EPSS Percentile
99.9th pct
GHSA ID
GitHub Severity
CRITICAL
SSVC Exploitation
—
SSVC Automatable
—
Vulnerability Class
—
Identity & Timeline
| Status | - |
| Assigning Authority | - |
| CVSS Version / Source | - |
| Reserved | - |
| Published | - |
| Patch Date (date_public) | - |
| Exploit DB Date | - |
| First GitHub PoC Date | - |
| Last Updated | - |
| Time to Patch (Days to fix) | - |
| Exploit Release Gap | - |
| PoC Release Gap | - |
| Exploit DB References | None identified |
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| No affected products specified. | ||
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