CRITICAL

CVE-2026-39987

Coreweave Marimo 2026-04-09 CVSS v3.1

CVSS

9.8

KEV

Description

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.

Summary dbcve.org

marimo before 0.23.0 has a pre-authentication RCE vulnerability in the terminal WebSocket endpoint /terminal/ws. This endpoint skips authentication validation (unlike /ws which calls validate_auth()), only checking running mode and platform support, allowing unauthenticated attackers to obtain a full PTY shell and execute arbitrary system commands.

Mitigation

Upgrade to marimo version 0.23.0 or later, which includes the fix for proper authentication validation on the /terminal/ws endpoint.

Proof of Concept

Patch Commit

Weakness (CWE)

CWE-306 Missing Authentication

EPSS Score

99.56%

Probability of exploitation in next 30 days

99.9th percentile

References

https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a Patch https://github.com/marimo-team/marimo/pull/9098 Issue Tracking, Patch https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc Exploit, Mitigation, Vendor Advisory https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-39987 US Government Resource https://www.sysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exploitation-in-under-10-hours Exploit, Third Party Advisory

View on dbcve.org

Base CVE data derived from NVD (public domain). Enrichment by dbcve.org (CC-BY-4.0). Fetched via API.

Back to CVE