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).

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Workaround

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History

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


Projects

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cve-icon MITRE

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cve-icon Vulnrichment

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cve-icon NVD

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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