Improper Certificate Validation and Insufficient Verification of Data Authenticity in Keycloak

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.8 · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS

• CVE-2019-3875: 0.29% estimated exploitation activity in the next 30 days; percentile 21.68 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A vulnerability was found in keycloak before 6.0.2. The X.509 authenticator supports the verification of client certificates through the CRL, where the CRL list can be obtained from the URL provided in the certificate itself (CDP) or through the separately configured path. The CRL are often available over the network through unsecured protocols ('http' or 'ldap') and hence the caller should verify the signature and possibly the certification path. Keycloak currently doesn't validate signatures on CRL, which can result in a possibility of various attacks like man-in-the-middle.

Published by the source

27 Jun 2019, 17:25 UTC

Last modified by the source

1 Feb 2023, 05:02 UTC

Source last checked

26 Oct 2026, 16:05 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-38cg-gg9j-q9j9

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# Patch Next advisory brief: CVE-2019-3875

Advisory: Improper Certificate Validation and Insufficient Verification of Data Authenticity in Keycloak
IDs: CVE-2019-3875, GHSA-38cg-gg9j-q9j9
Record: https://patchnext.com/advisories/cve-2019-3875 (revision 1, source checked 26 Oct 2026, 16:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.keycloak:keycloak-core: affected <= 6.0.1

## Suggested inspection (read-only)
- Maven org.keycloak:keycloak-core: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.keycloak:keycloak-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-38cg-gg9j-q9j9 (GitHub-reviewed advisory GHSA-38cg-gg9j-q9j9 lists affected ranges: Maven org.keycloak:keycloak-core >=0 <=6.0.1)

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