Unauthenticated Remote Code Execution In Marimo Notebook Server Cve 2026 39987
Sysdig, via The Hacker News on 2026-09-15, documented a fresh intrusion in which a human operator exploited this Marimo RCE and reached an SSH bastion within eight seconds, so any team still running a pre-0.23.0 Marimo instance reachable over the network should treat it as compromised-in-waiting.
Marimo versions before 0.23.0 expose a pre-authentication flaw that lets an unauthenticated remote attacker obtain shell access and run arbitrary system commands on the host serving the notebook. Twenty-one public exploits are catalogued in VulnCheck XDB.
Affected: marimo-team marimo < 0.23.0
Check the installed marimo package version on every host that runs a notebook server; anything below 0.23.0 is vulnerable. Identify which marimo instances are reachable from outside the host (bound to a non-loopback interface or exposed through a proxy). On exposed instances, review process and shell history for unexpected commands spawned by the marimo server process, and — per the Sysdig-described attack chain — review SSH authentication logs on bastions and other hosts for logins originating from the notebook host.
Upgrade marimo to 0.23.0 or later on every host. Until upgraded, remove network exposure of the notebook server (bind to localhost only or restrict access to trusted addresses) — no other vendor mitigation is given in the dossier.
The full story
This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.
