---
id: CVE-2026-85295
title: 'Chartbrew: Full account takeover via JWTs accepted under default CB_SECRET'
summary: >-
  Chartbrew is an open-source web application that can connect directly to
  databases and APIs and use the data to create charts. Prior to 5.2.3, four
  authentication helpers accepted session tokens signed with CB_SECRET,
  including known, we…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-1394
vendor: chartbrew
product: chartbrew
affected:
  - chartbrew < 5.2.3
published: '2026-11-06'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T21:05:31.286Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-85295'
references:
  - url: >-
      https://github.com/chartbrew/chartbrew/security/advisories/GHSA-qvv4-r3q6-8797
    label: >-
      https://github.com/chartbrew/chartbrew/security/advisories/GHSA-qvv4-r3q6-8797
  - url: >-
      https://github.com/chartbrew/chartbrew/commit/da8c71f156aaa13fbc7ead15a4726740fef2b3c5
    label: >-
      https://github.com/chartbrew/chartbrew/commit/da8c71f156aaa13fbc7ead15a4726740fef2b3c5
  - url: 'https://github.com/chartbrew/chartbrew/releases/tag/v5.2.3'
    label: 'https://github.com/chartbrew/chartbrew/releases/tag/v5.2.3'
tags:
  - cve.org
ingestedAt: '2026-11-06T22:04:56.332Z'
epss: 0.00397
epssPercentile: 0.34197
---

## Overview

Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. Prior to 5.2.3, four authentication helpers accepted session tokens signed with CB_SECRET, including known, weak, or shipped-default values. The vulnerable surface is session JWT fallback in server/modules/verifyToken.js, verifyUser.js, getUserFromToken.js, and socketManager.js across the API and socket layer. A stock source or repository Docker Compose deployment retains a known, weak, or default CB_SECRET and an attacker submits a forged HS256 token decoding to a target user id. Knowing the symmetric secret lets the attacker create a token that the legacy verification fallback accepts as the target user without that user's password or two-factor authentication. The condition includes stock source and repository Docker Compose installs and any otherwise known or weak CB_SECRET; a bare container where CB_SECRET is undefined is not affected by this fallback path. A forged session impersonates the chosen user across the entire API and socket layer and exercises that user's Chartbrew privileges. This issue is fixed in version 5.2.3.

## Affected

- `chartbrew < 5.2.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.