---
id: CVE-2026-85708
title: 'Chartbrew: Private chart data disclosure via forgeable CB_SECRET share tokens'
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, Chart
  share and embed tokens were signed with CB_SECRET, including known or
  shipped-default va…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cvssSource: cna
cwe:
  - CWE-347
vendor: chartbrew
product: chartbrew
affected:
  - chartbrew < 5.2.3
published: '2026-11-06'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T21:06:25.700Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-85708'
references:
  - url: >-
      https://github.com/chartbrew/chartbrew/security/advisories/GHSA-3chp-cr6f-hp63
    label: >-
      https://github.com/chartbrew/chartbrew/security/advisories/GHSA-3chp-cr6f-hp63
  - url: >-
      https://github.com/chartbrew/chartbrew/commit/07fff78db39e1c073a0301ac382c565268824e09
    label: >-
      https://github.com/chartbrew/chartbrew/commit/07fff78db39e1c073a0301ac382c565268824e09
  - 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: '2026-11-06T22:04:56.331Z'
epss: 0.00193
epssPercentile: 0.09081
---

## 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, Chart share and embed tokens were signed with CB_SECRET, including known or shipped-default values in stock source and repository Docker Compose installs. The vulnerable surface is chart share-token verification and filter-access routes for private charts. An attacker who knows the deployment's CB_SECRET targets a private chart that has been shared at least once so a share-policy row exists, then forges a Chart-subject token for that chart id. The known signing key permits valid Chart tokens, and the filter-access path accepts sequential integer ids without requiring a legitimate share link; token expiry and revocation are ineffective once the secret is known. The condition requires a known or default secret and an existing share-policy row. A bare container where CB_SECRET is undefined is outside this path, and a unique secret excludes it only while the value remains unknown and unpredictable. An unauthenticated attacker can enumerate integer ids and read arbitrary private chart data, including chartData, without possessing a legitimate share link. 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.