# CVE-2026-109081: Keycloak authorization bypass in Dynamic Client Registration

Source: https://junglewise.ai/threats/cve-2026-109081-a-flaw-was-found-in-keycloak-the-dynamic-client-registration-dcr  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-06. Updated: 2026-11-06  
License: CC BY 4.0 with a link back

CVE-2026-109081 · Severity: medium · CVSS 6.8 · Published 2026-11-06

Keycloak is an identity and access management system that organizations use to manage user authentication and authorization. An authenticated attacker with sufficient privileges can exploit a flaw in the Dynamic Client Registration endpoint to inject excessive roles, causing all clients in the system to generate abnormally large access tokens that consume memory and CPU resources, leading to service slowdown or outage.

Technologies: [Red Hat Keycloak](https://junglewise.ai/threats/technologies/red-hat-keycloak). Vendors: [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-109081 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-109081 being exploited in the wild.

**How severe is CVE-2026-109081?** Medium severity, with a CVSS score of 6.8, published 6 November 2026.

**Which products and versions are affected?** Red Hat Keycloak.

**Is there a fix for CVE-2026-109081?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-109081 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-109081?** Check whether you run Red Hat Keycloak. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Dynamic Client Registration (DCR) endpoint fails to properly validate authorization when processing the deprecated defaultRoles field, allowing an authenticated attacker with client creation privileges or a valid Initial Access Token to add excessive roles to the realm's default-roles composite. This causes all clients with full scope allowed (the default configuration) to receive bloated access tokens, resulting in memory and performance degradation. The vulnerability is classified as missing authorization (CWE-862) and requires high privileges to exploit.

## Affected products

- Red Hat Keycloak

## Timeline

- 2026-11-06: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-109081](https://access.redhat.com/security/cve/CVE-2026-109081)

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