CVE-2026-39987

CVE Enrichment

CVSS: 9.3 CRITICAL
EPSS: 37.87%
EPSS Percentile: 98.52%
CISA KEV: YES — Known Exploited Vulnerability

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.

Technical Details

CVSS Version: 4.0
CNA / NVD Source: security-advisories@github.com
Published: 10-Apr-2026 01:17
Last Modified: 17-Jun-2026 17:42
EPSS Date: 2026-10-11
CWE: CWE-306

CVSS 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 /
                            E:X /
                            CR:X /
                            IR:X /
                            AR:X /
                            MAV:X /
                            MAC:X /
                            MAT:X /
                            MPR:X /
                            MUI:X /
                            MVC:X /
                            MVI:X /
                            MVA:X /
                            MSC:X /
                            MSI:X /
                            MSA:X /
                            S:X /
                            AU:X /
                            R:X /
                            V:X /
                            RE:X /
                            U:X

CISA KEV Details

Date Added: 2026-04-23
Remediation Due: 2026-05-07
Known Ransomware Campaign 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.
Notes: https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc ; https://nvd.nist.gov/vuln/detail/CVE-2026-39987

Affected Products / Versions

coreweave / marimo
Version / affected range: * · before (exclusive) 0.23.0
cpe:2.3:a:coreweave:marimo:*:*:*:*:*:python:*:*

References

Last enrichment sync: 12-Oct-2026 09:30
Sources: NVD · FIRST EPSS · CISA KEV
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Reported Context (3)

CVE-2026-39987 Recorded Future Identifies 73 High-Impact Vulnerabilities in August, 70 Actively Exploited
Marimo's unauthenticated terminal WebSocket, CVE-2026-39987, affects versions before 0.23.0 and is in CISA's Known Exploited Vulnerabilities catalog. N4D Linux Malware Abuses MCP Tools and Scans for Exposed Services
CVE-2026-39987 Recorded Future Identifies 85 High-Impact Vulnerabilities in July, Many Actively Exploited

CVE (146)

Malware (10)

People (1)

Threat Actors (9)

MITRE ATT&CK (11)

Vendors (40)

Products (102)

Tools (14)

Industries (1)

Countries (1)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.