Missing Authentication for Critical Function in Marimo - CVE-2026-39987
Published: April 17, 2026
Vulnerability identifier: #VU126426
CSH Severity: Critical
CVSS v4.0: 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/E:A/U:Red
CVE-ID: CVE-2026-39987
CWE-ID: CWE-306
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vendor: Marimo
Affected software:
Marimo
Marimo
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary system commands.
The vulnerability exists due to missing authentication for a critical function in the terminal/ws WebSocket endpoint when handling WebSocket connections. A remote attacker can connect to the endpoint to execute arbitrary system commands.
The issue can expose a full interactive shell without authentication.
How to mitigate CVE-2026-39987
Install security update from vendor's website.