CVSS 4.0
9.3 criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NCVE-2026-39987
Critical (9.3) in Marimo Marimo. In CISA KEV since 2026-04-23. EPSS 100% chance of exploitation in the next 30 days. Fixed in marimo 0.23.0.
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.
Severity
CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- EPSS
- 100% chance of exploitation in the next 30 days; higher than 99% of CVEs (scores of 2026-10-31)
- CISA KEV
- listed 2026-04-23, due 2026-05-07
- CWE
- CWE-306
- Published
- Modified
- Record from
- the NVD, synced
Affected
- coreweave:marimo
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-2679-6mx9-h9xc | PyPI | marimo | <0.23.0 | 0.23.0 |
| PYSEC-2026-407 | PyPI | marimo | <0.23.0 | 0.23.0 |
References
- https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a
- https://github.com/marimo-team/marimo/pull/9098
- https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-39987
- https://www.sysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exploitation-in-under-10-hours