CVE-2026-4634

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/errata/RHSA-2026:6475	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6476	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6477	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6478	Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-4634	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2450250	Issue Tracking Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6475	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6476	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6477	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6478	Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-4634	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2450250	Issue Tracking Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4634.json

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:redhat:build_of_keycloak:-::::text-only:::
	cpe:2.3:a:redhat:build_of_keycloak:26.2::::text-only:::
	cpe:2.3:a:redhat:build_of_keycloak:26.2.15::::text-only:::
	cpe:2.3:a:redhat:build_of_keycloak:26.4::::text-only:::
	cpe:2.3:a:redhat:build_of_keycloak:26.4.11::::text-only:::

History

No history.

Information

Published : 2026-04-02 13:16

Updated : 2026-07-15 02:22

NVD link : CVE-2026-4634

Mitre link : CVE-2026-4634

CVE.ORG link : CVE-2026-4634

JSON object : View

Products Affected

redhat

build_of_keycloak

CWE

CWE-1050

Excessive Platform Resource Consumption within a Loop

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