# CVE-2026-39987: marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass

> CVE-2026-39987: marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2026-39987
Last updated: 2026-06-17T10:42:51Z

- Published: 2026-04-09 17:16 UTC · Updated: 2026-06-17 10:42 UTC · Assigner: GitHub\_M
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 99.6%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2026-04-23, federal due date 2026-05-07, ransomware use: Unknown
- CWE: CWE-306

## 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.

## CISA 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.

## Affected vendors and products

- marimo-team: marimo

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-39987)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-39987)
- [https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a](https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a)
- [https://github.com/marimo-team/marimo/pull/9098](https://github.com/marimo-team/marimo/pull/9098)
- [https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc](https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-39987 · Markdown: https://rewindex.com/cve/CVE-2026-39987.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-39987 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:26.539Z