Description

A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.

INFO

Published Date :

2026-04-02T12:44:53.424Z

Last Modified :

2026-04-02T16:35:02.691Z

Source :

redhat
AFFECTED PRODUCTS

The following products are affected by CVE-2026-4634 vulnerability.

Vendors Products
Redhat
  • Build Keycloak
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-4634.

URL Resource
https://access.redhat.com/errata/RHSA-2026:6475 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2026:6476 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2026:6477 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2026:6478 cve-icon cve-icon
https://access.redhat.com/security/cve/CVE-2026-4634 cve-icon cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2450250 cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-4634 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-4634 cve-icon
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CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
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Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact