Threats / Marimo / CVE-2026-39987
CVE-2026-39987
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Marimo vulnerability
Marimo contains a pre-authorization remote code execution vulnerability allowing unauthenticated attackers to gain shell access and execute arbitrary system commands.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can exploit missing authorization controls to execute arbitrary code on affected Marimo instances, leading to full system compromise without requiring valid credentials.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
7 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-23).
Probability (EPSS)
EPSS 0.95645 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Marimo, Marimo. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-306 Missing Authentication — weakness family: Authentication.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I identify a Marimo instance exposed on the network and send a crafted request to trigger code execution without authentication.
Business
The organization's Marimo deployment becomes an entry point for unauthorized access to critical systems.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary system commands through the vulnerability to establish persistent shell access on the compromised host.
Business
Attackers gain foothold for lateral movement, data exfiltration, and further infrastructure compromise.
3
Lateral reach — past segmentation narrative 3
Attacker
I leverage the shell access to escalate privileges, access sensitive data, or deploy additional malware.
Business
Confidentiality, integrity, and availability of business systems and data are severely compromised.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05