CVE-2026-39987

Summary

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

VendorProductVersion RangeStatus
marimo-teammarimo< 0.23.0affected

Weaknesses

  • CWE-306: CWE-306: Missing Authentication for Critical Function

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: active
    • Automatable: yes
    • Technical Impact: total

Additional References

References