Istio is an open platform to connect, manage, and secure microservices. Prior to versions 1.28.6 and 1.29.2, when a RequestAuthentication resource is created with a jwksUri pointing to an internal service, istiod makes an unauthenticated HTTP GET request to that URL without filtering out localhost or link local ips. This can result in sensitive data being distributed to Envoy proxies via xDS configuration. This issue has been patched in versions 1.28.6 and 1.29.2.