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Vulnerability record · CVE-2020-27838 · published 8 March 2021

CVE-2020-27838: Redhat keycloak improper authentication vulnerability

Redhat · Keycloak

A flaw was found in keycloak in versions prior to 13.0.0. The client registration endpoint allows fetching information about PUBLIC clients (like client secret) without authentication which could be an issue if the same PUBLIC client changed to CONFIDENTIAL later. The highest threat from this vulnerability is to data confidentiality.

6.5 CVSS 3.1 Medium EPSS 18% · top 2.9% CWE-287 · Improper authentication
6.5CVSS 3.1 base score, v2 4.3
18%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A flaw was found in keycloak in versions prior to 13.0.0. The client registration endpoint allows fetching information about PUBLIC clients (like client secret) without authentication which could be an issue if the same PUBLIC client changed to CONFIDENTIAL later. The highest threat from this vulnerability is to data confidentiality.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugzilla.redhat.com/show_bug.cgi?id=1906797 Issue TrackingVendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1906797 Issue TrackingVendor Advisory

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Source: NIST National Vulnerability Database (record CVE-2020-27838), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.