CVE-2026-39987 in coreweave marimo
LogPulse has a published detection rule for this CVE: it raises a notable when someone tries to exploit it.
What the vulnerability is
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.
Affected software: coreweave marimo
Scores
- CVSS: 9.3 (critical)
- EPSS: 99.74% chance of exploitation in the next 30 days
- CISA KEV: Known exploited, listed 2026-04-23
- Published: 2026-04-09
What LogPulse has for it
- Detection rule: Yes, published
- Agent check (vulnerable version): No
- Mitigation: No
Source data: NIST NVD, CISA KEV and FIRST EPSS. LogPulse processes new CVEs every hour.
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