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TI-2026-28840 Aliases CVE-2026-39987GHSA-2679-6mx9-h9xc

marimo Affected by Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass

Priority CRITICAL 99Exploited in the wildCWE-306Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-306.

Summary

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.

Why it matters now

Exploitation Active In CISA KEV since 2026-04-23CISA due date 2026-05-07
EPSS 0.99743 99th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed marimo (marimo-team): 0.23.0marimo (PyPI): 0.23.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Active
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
marimo-teammarimobefore 0.23.00.23.0Patch availableCNA
—marimo (PyPI)before 0.23.00.23.0Patch availableGHSA-2679-6mx9-h9xc
  • marimo Vendormarimo-team Affected before 0.23.0 Fixed in 0.23.0 Patch available CNA
  • marimo (PyPI) Vendor— Affected before 0.23.0 Fixed in 0.23.0 Patch available GHSA-2679-6mx9-h9xc

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:coreweave:marimo:*:*:*:*:*:python:*:*before 0.23.0VulnerableCoreweave
  • cpe:2.3:a:coreweave:marimo:*:*:*:*:*:python:*:* Versions before 0.23.0 Vulnerable ·Coreweave

Remediation

  • Fix · CNA marimo (marimo-team) Fixed in 0.23.0
  • Fix · GHSA-2679-6mx9-h9xc marimo (PyPI) Fixed in 0.23.0 Advisory →

Timeline

  1. 2026-04-23 Added to CISA KEV
  2. 2026-10-02 Threatist record created from CVE-2026-39987
  3. 2026-10-03 Alias added: GHSA-2679-6mx9-h9xc
  4. 2026-10-25 EPSS moved to the 99th percentile and above

References

Exploit 2

Patch 2

Advisory 1

Other 3

  • TI-2026-52802 marimo < 0.23.15 Code Injection via MCP Server Configuration CVSS 4.0HIGH 8.7
  • TI-2026-47772 marimo < 0.23.15 API Key Exfiltration via Malicious Notebook PEP-723 Metadata CVSS 4.0HIGH 7.1
  • TI-2026-39264 marimo < 0.23.9 XSS via file Query Parameter in assets.py CVSS 4.0MEDIUM 5.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences