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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-4634

Keycloak: keycloak: denial of service via excessive processing of openid connect scope parameters

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Status
Published
Published
Updated
Assigning organization
redhat

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Red Hat Red Hat build of Keycloak 26.2

Default version status: affected

  • 26.2.15-1 to < *unaffected

Red Hat Red Hat build of Keycloak 26.2

Default version status: affected

  • 26.2-18 to < *unaffected

Red Hat Red Hat build of Keycloak 26.2

Default version status: affected

  • 26.2-18 to < *unaffected

Red Hat Red Hat build of Keycloak 26.2.15

Default version status: unaffected

Red Hat Red Hat build of Keycloak 26.4

Default version status: affected

  • 26.4.11-1 to < *unaffected

Red Hat Red Hat build of Keycloak 26.4

Default version status: affected

  • 26.4-14 to < *unaffected

Red Hat Red Hat build of Keycloak 26.4

Default version status: affected

  • 26.4-14 to < *unaffected

Red Hat Red Hat build of Keycloak 26.4.11

Default version status: unaffected

Red Hat Red Hat Single Sign-On 7.6.13

Default version status: unaffected

Red Hat Red Hat Single Sign-On 7.6 for RHEL 7

Default version status: affected

  • 0:18.0.20-1.redhat_00001.1.el7sso to < *unaffected

Red Hat Red Hat Single Sign-On 7.6 for RHEL 8

Default version status: affected

  • 0:18.0.20-1.redhat_00001.1.el8sso to < *unaffected

Red Hat Red Hat Single Sign-On 7.6 for RHEL 9

Default version status: affected

  • 0:18.0.20-1.redhat_00001.1.el9sso to < *unaffected

Red Hat RHEL-8 based Middleware Containers

Default version status: affected

  • 7.6-85 to < *unaffected

References