GHSA-v3f7-2p4r-mwfw Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass

• Maven org.keycloak:keycloak-services: < 26.6.4 → fixed in 26.6.4

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.