CVE-2026-107889
Medium
Description
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.
SeverityMedium
CVSS5.5
Exploit probability—
Product
Red Hat Build of Keycloak
PublishedOct 9, 2026
First seenOct 9, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Red Hat Build of Keycloak | No range specified | — |
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