CVE-2026-107889: Red Hat Build Of Keycloak

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

A flaw was found in the login theme rendering component of Keycloak. The issue occurs because the security filter responsible for cleaning user input can be bypassed, allowing a realm administrator to store malicious scripts in display fields. This could result in unauthorized JavaScript execution in the browsers of users visiting the login page, potentially leading to data exposure or session interference.

Affected products

• Red Hat Red Hat Build Of Keycloak
• Red Hat Red Hat Single Sign-On 7

Published 2026-10-09. Last modified 2026-10-09.