by Kastro
Paper/Archive/CVE-2026-39987

CVE-2026-39987

marimo-team marimo — marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass

KEV · due 7 MayEPSS 100%public exploitSSVC actCVSS 9.3
critical.is priorityof 100
98
CVSS 9.3 (CNA)9.3 / 10 × 3027.9In CISA KEV+3030.0EPSS percentile 99.9.999 × 2020.0Exploit: SSVC active+1010.0SSVC exploitation: active+1010.0
Description · from the CVE record

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

ProductAffectedFixed inSource
marimo< 0.23.0–CNA

Scores by source

GitHub_M (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: active · Automatable: yes · Technical impact: total

References

refgithub.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xcrefgithub.com/marimo-team/marimo/pull/9098refgithub.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12awriteupsysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exploitation-in-under-10-hoursrefcisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-39987kevcisa.gov/known-exploited-vulnerabilities-catalog