Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/marimo-team/marimo/commit/fdd55c8cf6260ae23bb411dc9d9269def5c
- https://github.com/marimo-team/marimo/pull/9789
- https://github.com/marimo-team/marimo/releases/tag/0.23.9
- https://www.vulncheck.com/advisories/marimo-xss-via-file-query-parameter-in-asse
FAQ
What is CVE-2026-54386?
CVE-2026-54386 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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 o...
How severe is CVE-2026-54386?
CVE-2026-54386 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-54386?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.