CVE-2026-39987: marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass
In CISA’s Known Exploited Vulnerabilities catalog: Marimo Remote Code Execution Vulnerability.
Added , federal remediation due . Known ransomware use: Unknown.
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H · CWE-306
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
marimo-team: marimo
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a (opens in new tab)
- github.com/marimo-team/marimo/pull/9098 (opens in new tab)
- github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)