Page generated: 08 Nov 2026, 09:43 UTC
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CVE-2026-39987

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. Unl…

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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.
CVSS 9.3 (CRITICAL) KEV: KNOWN CATALOG

Attention and evidence

HYPE SCORE
0.0/10
REALITY · THREAT PRIORITY
8.9/10
General review priority; not probability

Evidence confidence: Exploitation recorded

Why this priority?
  • Recorded exploitation baseline: +7.00
  • Technical severity: CVSS 9.3: +1.40
  • Fresh EPSS: 99.74%: +0.50

General review priority, not probability, victim count or asset-specific risk. A range covers missing CVSS/EPSS inputs within the current evidence state.

Sources: 11 documents and public datasets.

Hype components

Headline sample (25%)
0/100
Press, 30 days (60%)
0/100
Grounded branding (15%)
0/100
HYPE TOTAL0/100

Sources and documents

The Hacker News
Press · 31 Jul 2026, 07:00 · Chinese Hacker Commands DeepSeek via Telegram to Launch Autonomous Attacks - The Hacker News
The Hacker News
Press · 17 Jul 2026, 07:00 · New NadMesh Botnet Hunts Exposed AI Services for Cloud Keys and Kubernetes Tokens - The Hacker News
The Hacker News
Press · 29 May 2026, 07:00 · Attackers Use LLM Agent for Post-Exploitation After Marimo CVE-2026-39987 Exploit - The Hacker News
Recorded Future
Press · 15 May 2026, 07:00 · April 2026 CVE Landscape - Recorded Future
CyberSecurityNews
Press · 17 Apr 2026, 07:00 · Attackers Weaponize CVE-2026-39987 to Spread Blockchain-Based Backdoor Via Hugging Face - CyberSecurityNews
See all 11 source documents
Resecurity
Press · 16 Apr 2026, 07:00 · Marimo Pre-Auth RCE via Unauthenticated WebSocket Terminal (CVE-2026-39987) - Resecurity
BleepingComputer
Press · 16 Apr 2026, 07:00 · Hackers exploit Marimo flaw to deploy NKAbuse malware from Hugging Face - BleepingComputer
CCB Belgium
Press · 13 Apr 2026, 07:00 · Warning: Critical Pre-Authentication Remote Code Execution in Marimo exploited in the wild, Patch Immediately! - CCB Belgium
Security Affairs
Press · 11 Apr 2026, 07:00 · CVE-2026-39987: Marimo RCE exploited in hours after disclosure - Security Affairs
The Hacker News
Press · 10 Apr 2026, 07:00 · Marimo RCE Flaw CVE-2026-39987 Exploited Within 10 Hours of Disclosure - The Hacker News
Endor Labs
Press · 09 Apr 2026, 07:00 · Root in One Request: Marimo's Critical Pre-Auth RCE (CVE-2026-39987) - Endor Labs

Score evolution

● Hype   ● Reality

Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.

First record: hype 0.0 · reality 8.9 (2026-11-02 15:14). The curve appears once the score changes.

Public exploit evidence

12

Public exploit entries / repo candidates

See 12 repos with metrics
RepositoryStarsForksLanguageUpdated
M3PH1569/CVE-2026-39987-POC50Python19 Jul 2026, 11:04
Wind010/CVE-2026-39987_PoC10Python03 Aug 2026, 07:23
alreadyClosed/CVE-2026-3998700Python07 Aug 2026, 07:33
fevar54/marimo_CVE-2026-39987_RCE_PoC01Python13 Apr 2026, 18:14
jasonbernier/CVE-2026-3998700Python04 Aug 2026, 18:03
julichaan/CVE-2026-39987_POC00Python11 Sep 2026, 18:30
lunacysoft/CVE-2026-39987-POC-Marimo00Python24 Oct 2026, 06:23
MADA0L/CVE-2026-39987-Poc00Python10 Aug 2026, 03:52
matesz44/cve-2026-3998700Go12 Aug 2026, 19:17
mfahdk/CVE-2026-39987_RCE_PoC00Python20 Sep 2026, 12:44
stapat1245/CVE-2026-39987-PoC00Python07 Sep 2026, 20:10
vanhari/CVE-2026-3998700Python02 Aug 2026, 17:40
Public exploit evidence
Evidence context and dated references

Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs.

Evidence in context

Confidence in exploitation evidence
Exploitation recorded
Priority basis
Recorded exploitation; CVSS 9.3; EPSS 99.7%
Attention, last 30 days
0 distinct story titles; 0 press documents; 0 publisher domains.
Technical potential
network access, no prior privileges, no user interaction.
Observed activity
Exploitation recorded in CISA KEV.
Known scale
Not quantified.
Evidence confidence basis
Trusted exploitation confirmation

Score evaluated: 2026-11-05 14:00:08.932646+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z

Source event timeline
First press mention
09 Apr 2026, 07:00
Published
09 Apr 2026, 17:16
Added to the CISA KEV catalog
23 Apr 2026, 00:00
Latest press mention
31 Jul 2026, 07:00
Score calculated
05 Nov 2026, 14:00
PoCs on GitHub
12 repositories