CVE-2026-27605: Chartbrew: Stored Cross-Site Scripting (XSS) via File Upload API

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-06 · updated 2026-06-17
Weakness: CWE-79

Description

Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. Prior to version 4.8.4, the application allows uploading files (project logos) without validating the file type or content. It trusts the extension provided by the user. These files are saved to the uploads/ directory and served statically. An attacker can upload an HTML file containing malicious JavaScript. Since authentication tokens are likely stored in localStorage (as they are returned in the API body), this XSS can lead to account takeover. This issue has been patched in version 4.8.4.

Affected products

chartbrew: before 4.8.4 — fixed in 4.8.4

How to fix

Upgrade to a fixed version: chartbrew 4.8.4. Check the vendor advisory for mitigations.

References

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