TI-2026-39264 Aliases CVE-2026-54386 GHSA-8m59-7xv8-735h

marimo < 0.23.9 XSS via file Query Parameter in assets.py

LOW 23CWE-79Published 2026-06-17 · Updated 2026-10-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: Active
Attack complexity: Low
Attack requirements: None
Impact type: Cross-site scripting
Confidentiality · integrity · availability: None · None · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00239 15th percentileScored 2026-11-07

Fix Fixed marimo (marimo-team): 0.23.9marimo (PyPI): 0.23.9

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
marimo-team	marimo	before 0.23.9	0.23.9	Patch available	CNA
—	marimo (PyPI)	before 0.23.9	0.23.9	Patch available	GHSA-8m59-7xv8-735h

marimo Vendormarimo-team Affected before 0.23.9 Fixed in 0.23.9 Patch available CNA
marimo (PyPI) Vendor— Affected before 0.23.9 Fixed in 0.23.9 Patch available GHSA-8m59-7xv8-735h

Remediation

Fix · CNA marimo (marimo-team) Fixed in 0.23.9
Fix · GHSA-8m59-7xv8-735h marimo (PyPI) Fixed in 0.23.9 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-54386
2026-10-03 Alias added: GHSA-8m59-7xv8-735h

References

Patch 1

https://github.com/marimo-team/marimo/commit/fdd55c8cf6260ae23bb411dc9d9269def5cf75d6

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-54386

Other 3

TI-2026-52802 marimo < 0.23.15 Code Injection via MCP Server Configuration CVSS 4.0HIGH 8.7
TI-2026-47772 marimo < 0.23.15 API Key Exfiltration via Malicious Notebook PEP-723 Metadata CVSS 4.0HIGH 7.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences