Cross-Site Scripting Vulnerability in Keycloak Affects Multiple Users
CVE-2026-9086

7.3HIGH

Key Information:

Vendor

Red Hat
Status
Red Hat Build Of Keycloak
Vendor
CVE Published:
25 June 2026

What is CVE-2026-9086?

A vulnerability has been identified in Keycloak allowing remote attackers with administrative privileges to bypass client URI validation. By registering a malicious client with a specially crafted redirect URI, utilizing a case-insensitive 'javascript:' or 'data:' scheme, attackers can exploit this Cross-Site Scripting vulnerability. This can lead to arbitrary code execution within the Keycloak origin, particularly when victims inadvertently click on malicious links during login or logout processes.

References

https://access.redhat.com/security/cve/CVE-2026-9086
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2480170
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
7.3
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank saku0512 for reporting this issue.
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