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Fencer Intel
critical 9.8

CVE-2026-85295 json

Chartbrew: Full account takeover via JWTs accepted under default CB_SECRET

published 2mo ago modified 2d ago also EUVD-2026-118502 , GHSA-qvv4-r3q6-8797

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository chartbrew/chartbrew. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

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, 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.

Patch / fix

  • depomo chartbrew 5.2.3

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
2d ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • chartbrew chartbrew

Classification

Weakness
  • CWE-1394 Use of Default Cryptographic Key

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of chartbrew/chartbrew published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.