CVE-2026-109081

CVE-2026-109081

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).

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-109081?
CVE-2026-109081 is a medium-severity vulnerability, classified under Missing Authorization. CVSS score: 6.8/10. Published 2026-11-06.
How severe is CVE-2026-109081?
Medium severity. CVSS v3 base score is 6.8 out of 10.