GHSA-v3f7-2p4r-mwfw - Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass
### 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.
HIGH
Severity & confidence
Source severityhigh
Platform severityhigh
Confidencemedium
Exploitationunknown
CVSS7.3
Affected
Vendorsorg.keycloak:keycloak-services
Productsorg.keycloak:keycloak-services
Reporting sources (1)
GitHub Security Advisories
Timeline & provenance
Published2026-10-29T16:39:03
Last updated2026-11-05T15:48:34
Ingested2026-10-29T16:43:21
FreshnessNEAR-REAL-TIME
Threat typeadvisory
Recommended action
Review the advisory and upgrade affected packages to the first patched version.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a single or secondary source; treat as indicative, verify before acting.
Source type: vendor ยท Original: GitHub Security Advisories