CVE-2026-109081— Keycloak-services: keycloak-services: injection of roles into realm default-roles via dcr endpoint

Quick assessment

Affected

Red Hat Red Hat build of Keycloak 26.6.8

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Keycloak 中发现一处漏洞。动态客户端注册（DCR）端点在处理已弃用的字段时，未能正确验证授权。拥有客户端创建权限的已认证攻击者，或持有初始访问令牌（IAT）的攻击者，可向领域的默认角色配置中注入大量角色。这会导致该领域内的所有客户端生成臃肿的访问令牌，进而引发性能下降和内存消耗增加，最终可能导致拒绝服务（DoS）攻击。

CVSS 6.8 · Medium Updated Nov 06, 2026

Possible ATT&CK Techniques 2 AI

T1499 · Endpoint Denial of Service T1499.003 · Application Exhaustion Flood

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Vulnerability Information

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Vulnerability Title

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

Source: CVE Program / CVE List V5

Vulnerability 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).

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

Source: CVE Program / CVE List V5

Vulnerability Type

授权机制缺失

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE
Red Hat	Red Hat build of Keycloak 26.6.8	-	`cpe:/a:redhat:build_keycloak:26.6::el9`
Red Hat	Red Hat build of Keycloak 26.6.8	-	`cpe:/a:redhat:build_keycloak:26.6::el9`
Red Hat	Red Hat Single Sign-On 7	-	`cpe:/a:redhat:red_hat_single_sign_on:7`

II. Public POCs for CVE-2026-109081

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-109081

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Other References for CVE-2026-109081 (2)

https://access.redhat.com/security/cve/CVE-2026-109081 vdb-entry x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:95761 vendor-advisory x_refsource_REDHAT

https://www.cve.org/CVERecord?id=CVE-2026-109081

Same Patch Batch · Red Hat · 2026-11-06 · 15 CVEs total

CVE-2026-19688	6.8 MEDIUM	Keycloak-services: keycloak-services: admin api missing audience check
CVE-2026-123037	6.7 MEDIUM	Ansible-core: user module generate_ssh_key follows a symlinked ~/.ssh enabling local privi
CVE-2026-96547	6.5 MEDIUM	Keycloak-services: keycloak-services: dcr registration-time claim-path gap allows forging
CVE-2026-97848	6.5 MEDIUM	Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sa
CVE-2026-9797	6.5 MEDIUM	Keycloak: keycloak: privilege escalation via client authentication manipulation by an auth
CVE-2026-107124	6.4 MEDIUM	Keycloak-services: keycloak-services: oidc logout endpoint session fixation via id_token_h
CVE-2026-97367	6.4 MEDIUM	Keycloak-services: keycloak-services: dcr azp and sid claim substitution allows account re
CVE-2026-120749	6.2 MEDIUM	Dbus: dbus-daemon: dbus-daemon aborts (reply_serial != 0) when a broadcast from the driver
CVE-2026-96460	5.4 MEDIUM	Keycloak-services: keycloak-services: indefinite access token renewal via standard token e
CVE-2026-92856	4.9 MEDIUM	Keycloak-services: keycloak-services: saml broker ignores proxyrestriction delegation cons
CVE-2026-121837	4.3 MEDIUM	Quarkus-rest-data-panache: quarkus-rest-data-panache: getter-level @securefield ignored fo
CVE-2026-96447	4.2 MEDIUM	Keycloak-services: keycloak-services: stateless token preferred_username fallback enables
CVE-2026-83493		Distributed-workloads: github actions pinned by mutable tag/branch, including third-party
CVE-2026-83494		Training-operator: pytorchjob validateupdate casts oldjob from newobj, bypassing managedby

IV. Related Vulnerabilities

Same product: Red Hat build of Keycloak 26.6.8

Same vendor: Red Hat

Same weakness: CWE-862