CVE-2020-27838

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 17.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-03-08 · updated 2026-06-17
Weakness: CWE-287

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.

Affected products

Keycloak: before 13.0.0 — fixed in 13.0.0
Red Hat Single Sign-On: 7.0

How to fix

Upgrade to a fixed version: Keycloak 13.0.0. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1906797
https://bugzilla.redhat.com/show_bug.cgi?id=1906797

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