CVE-2026-39987

critical

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.

References

Exploits
More

https://www.bleepingcomputer.com/news/security/hackers-exploit-marimo-flaw-to-deploy-nkabuse-malware-from-hugging-face/

https://www.bleepingcomputer.com/news/security/critical-marimo-pre-auth-rce-flaw-now-under-active-exploitation/

https://securityaffairs.com/190623/hacking/cve-2026-39987-marimo-rce-exploited-in-hours-after-disclosure.html

https://www.securityweek.com/critical-marimo-flaw-exploited-hours-after-public-disclosure/

https://thehackernews.com/2026/04/marimo-rce-flaw-cve-2026-39987.html

https://webflow.sysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exploitation-in-under-10-hours

https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc

https://github.com/marimo-team/marimo/pull/9098

https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a

Details

Source: Mitre, NVD

Published: 2026-04-09

Updated: 2026-04-13

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 9.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: Critical

EPSS

EPSS: 0.02704