A flaw was identified in Keycloak’s OpenID Connect Dynamic Client Registration feature when clients authenticate using private_key_jwt. The issue allows a client to specify an arbitrary jwks_uri, which Keycloak then retrieves without validating the destination. This enables attackers to coerce the Keycloak server into making HTTP requests to internal or restricted network resources. As a result, attackers can probe internal services and cloud metadata endpoints, creating an information disclosure and reconnaissance risk.
{
"cwe_ids": [
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-21T21:55:11Z",
"nvd_published_at": "2026-01-20T13:16:03Z",
"severity": "MODERATE"
}