# CVE-2026-85295: Chartbrew: Full account takeover via JWTs accepted under default CB_SECRET

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- chartbrew / chartbrew: < 5.2.3 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 9.8 (critical); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-1394

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/chartbrew/chartbrew/security/advisories/GHSA-qvv4-r3q6-8797 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/chartbrew/chartbrew/commit/da8c71f156aaa13fbc7ead15a4726740fef2b3c5 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/chartbrew/chartbrew/releases/tag/v5.2.3 (CNA: GitHub_M; x_refsource_MISC)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-85295; retrieved 2026-11-06; source updated 2026-11-06

Revision: 35085eeea72dd023b71a702cdc3442869f933627292e0c352880c9df45c4925f

Canonical: https://y2.dev/cve/CVE-2026-85295

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