A vulnerability in ingress-nginx controller allows configuration injection via unsanitized 'mirror-target' and 'mirror-host' annotations. This flaw can lead to arbitrary code execution within the ingress-nginx controller and disclosure of Secrets accessible to it. The default installation grants the controller access to all cluster-wide Secrets, increasing the impact. The issue affects versions prior to 1.11.5 and versions from 1.12.0-beta.0 up to but not including 1.12.1. Fixed in versions 1.11.5 and 1.12.1.