Capsule is a multi-tenancy and policy-based framework for Kubernetes. In Capsule v0.7.0 and earlier, the tenant-owner can patch any arbitrary namespace that has not been taken over by a tenant (i.e., namespaces without the ownerReference field), thereby gaining control of that namespace. Version 0.7.1 contains a patch.

Capsule tenant owner with "patch namespace" permission can hijack system namespaces