Description
A flaw was found in Keycloak. The Dynamic Client Registration (DCR) endpoint does not properly validate authorization when processing the deprecated defaultRoles field. An authenticated attacker with client creation privileges or an Initial Access Token (IAT) can inject excessive roles into the realm's default roles configuration. This causes clients across the realm to generate bloated access tokens, resulting in performance and memory degradation that can lead to a Denial of Service (DoS).
Published: 2026-11-06
Score: 6.8 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Tracking

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Advisories

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History

Fri, 06 Nov 2026 06:15:00 +0000

Type Values Removed Values Added
Title Denial of Service via Default Role Injection in Keycloak DCR Keycloak-services: keycloak-services: injection of roles into realm default-roles via dcr endpoint
First Time appeared Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
References

Fri, 06 Nov 2026 03:15:00 +0000

Type Values Removed Values Added
Title Denial of Service via Default Role Injection in Keycloak DCR

Fri, 06 Nov 2026 03:00:00 +0000

Type Values Removed Values Added
First Time appeared Keycloak
Keycloak keycloak
Vendors & Products Keycloak
Keycloak keycloak

Fri, 06 Nov 2026 00:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in Keycloak. The Dynamic Client Registration (DCR) endpoint does not properly validate authorization when processing the deprecated defaultRoles field. An authenticated attacker with client creation privileges or an Initial Access Token (IAT) can inject excessive roles into the realm's default roles configuration. This causes clients across the realm to generate bloated access tokens, resulting in performance and memory degradation that can lead to a Denial of Service (DoS).
Weaknesses CWE-862
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H'}

threat_severity

Moderate


Subscriptions

Keycloak Keycloak
Redhat Build Keycloak Red Hat Single Sign On
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-11-06T05:57:29.220Z

Reserved: 2026-10-12T05:43:18.181Z

Link: CVE-2026-109081

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-06T06:16:39.290

Modified: 2026-11-06T06:16:39.410

Link: CVE-2026-109081

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-11-05T00:00:00Z

Links: CVE-2026-109081 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-11-06T03:00:16Z

Weaknesses