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Fencer Intel
high 7.5

CVE-2026-85708 json

Chartbrew: Private chart data disclosure via forgeable CB_SECRET share tokens

published 2mo ago modified yesterday also EUVD-2026-118503 , GHSA-3chp-cr6f-hp63

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
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
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, 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.

Patch / fix

  • depomo chartbrew 5.2.3

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
yesterday

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/chartbrew/chartbrew/security/advisories/GHSA-3chp-cr6f-hp63 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • chartbrew chartbrew

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

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.