CVE-2026-109081

Keycloak-services: keycloak-services: injection of roles into realm default-roles via dcr endpoint

Published Nov 6, 2026 CVSS 3.1 · 6.8 Medium EPSS < 1% KEV · Not listed
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).

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

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.6::el9
References
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
Type Values Removed Values Added
Title Denial of Service via Default Role Injection in Keycloak DCR
Type Values Removed Values Added
First Time appeared Keycloak
Keycloak keycloak
Vendors & Products Keycloak
Keycloak keycloak
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

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 10, 2026, 7:40 PM
Reserved
Oct 12, 2026, 5:43 AM
Status
Awaiting Analysis
Published
Nov 6, 2026, 6:16 AM
Modified
Nov 10, 2026, 8:17 PM
Severity
Moderate
Public date
Nov 5, 2026, 12:00 AM