---
id: "CVE-2026-85708"
page: "https://infrastack.ai/live/CVE-2026-85708"
kind: "vulnerability"
aliases: ["CVE-2026-85708"]
title: "Chartbrew: forged share tokens expose private chart data when secret is default"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["chartbrew", "docker-compose", "package", "self-hosted"]
not_affected_if: ["managed-hosting", "unique-cb-secret", "version-5.2.3-or-later"]
published_at: "2026-11-06T21:17:11+00:00"
first_seen_at: "2026-11-06T21:45:08+00:00"
updated_at: "2026-11-06T21:46:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85708", "first_seen_at": "2026-11-06T21:45:08+00:00"}]
exploit_sources: []
---

# Chartbrew: forged share tokens expose private chart data when secret is default

Link for people: https://infrastack.ai/live/CVE-2026-85708 (this .md is for agents)

Chartbrew signed chart share and embed tokens with CB_SECRET, which in stock source and repository Docker Compose installs is a known or shipped default value. An attacker who knows that secret can forge tokens and read private chart data, including chartData, by enumerating integer chart ids.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the `CB_SECRET` value in your Chartbrew environment or Docker Compose file and confirm it is not a shipped default from the stock source or repository.
- Check the installed Chartbrew version; versions before `5.2.3` are affected.

## Fix

- Chartbrew: move to `5.2.3` or later.

## Timeline

- 2026-11-06T21:45:08+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-85708

## Documents

- [advisory] Vendor advisory: github.com https://github.com/chartbrew/chartbrew/security/advisories/GHSA-3chp-cr6f-hp63
- [fix] Patch: github.com https://github.com/chartbrew/chartbrew/commit/07fff78db39e1c073a0301ac382c565268824e09
- [fix] Release notes: github.com https://github.com/chartbrew/chartbrew/releases/tag/v5.2.3

## From the sources

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.

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