CVE-2026-54386
marimo contains a reflected cross-site scripting vulnerability in the notebook page
Description
marimo before 0.23.9 contains a reflected cross-site scripting vulnerability in the notebook page that allows unauthenticated attackers to inject arbitrary JavaScript by exploiting improper escaping of single quotes in the file query parameter reflected into an inline JavaScript string literal. Attackers can craft a malicious link with a payload beginning with __new__ to bypass the 404 check and inject JavaScript into the page, which executes without Content-Security-Policy restrictions in the origin of a victim's marimo server.
How to fix CVE-2026-54386
To remediate CVE-2026-54386, upgrade the affected package to a fixed version below.
- —upgrade to 0.23.9 or later
Is CVE-2026-54386 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-54386.
Affected packages (1)
- from 0, < 0.23.9
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N |
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |