A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with `manage-client` permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive `javascript:` or `data:` scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.
History

Fri, 26 Jun 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat build Of Keycloak
Vendors & Products Redhat build Of Keycloak

Fri, 26 Jun 2026 07:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak:26.4::el9
References

Fri, 26 Jun 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Thu, 25 Jun 2026 20:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.6::el9
References

Thu, 25 Jun 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 25 Jun 2026 16:45:00 +0000

Type Values Removed Values Added
Description A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with `manage-client` permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive `javascript:` or `data:` scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.
Title Keycloak: keycloak: cross-site scripting (xss) via case-insensitive uri validation bypass
First Time appeared Redhat
Redhat build Keycloak
Weaknesses CWE-79
CPEs cpe:/a:redhat:build_keycloak:
Vendors & Products Redhat
Redhat build Keycloak
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-06-26T06:26:53.231Z

Reserved: 2026-05-20T14:44:12.702Z

Link: CVE-2026-9086

cve-icon Vulnrichment

Updated: 2026-06-25T17:59:52.871Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Important

Publid Date: 2026-06-25T15:58:33Z

Links: CVE-2026-9086 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-06-26T09:36:52Z