**What is the impact?**

A user that is authorized to create pods can make use of any existing PodSecurityPolicy, even ones they are not authorized to use.

**How can I mitigate this prior to installing 1.5.5?**

1. Export existing PodSecurityPolicy objects:
  * `kubectl get podsecuritypolicies -o yaml > psp.yaml`

images pull` before each `kubeadm init`. If you don't want the kubelet to pull any images at `kubeadm init` time, for example if you don't have an internet connection, you can also run `kubeadm config images pull` before `kubeadm init` or side-load the images some other way (such as `docker load -i image.tar`). Having the images locally cached will result in no pull at runtime, which makes it possible to run without any internet connection. ([#64096](https://github.com/kubernetes/kubernetes/pull/64096),...

- Fixed a bug where init containers may fail to start due to a temporary container runtime failure. ([#127214](https://github.com/kubernetes/kubernetes/pull/127214), [@SergeyKanzhelev](https://github.com/SergeyKanzhelev)) [SIG Node]

- DRA: When the prioritized list feature was used in a request and the resulting number of allocated devices exceeded the number of allowed devices per claim, the scheduler aborted the attempt to allocate devices early. Previously, it tried to many different combinations, which could take a long time. ([#130593](https://github.com/kubernetes/kubernetes/pull/130593), [@mortent](https://github.com/mortent)) [SIG Apps, Node, Scheduling and Testing]

  - true/strict - perform validation and error the request on any invalid fields in the ojbect. It will attempt to perform server-side validation if it is enabled on the apiserver, otherwise it will fall back to client-side validation.

  - `spec.signerName` is now required, and requests for `kubernetes.io/legacy-unknown` are not allowed to be created via the `certificates.k8s.io/v1` API
  - `spec.usages` is now required, may not contain duplicate values, and must only contain known usages
  - `status.conditions` may not contain duplicate types
  - `status.conditions[*].status` is now required

*   The admission webhook configurations API, part of the admissionregistration API, is now at v1beta1. Delete any existing webhook configurations before you upgrade, and update your configuration files to use the latest API. For this and...

- Using exec auth plugins with kubectl no longer results in warnings about constructing many client instances from the same exec auth config. ([#97857](https://github.com/kubernetes/kubernetes/pull/97857), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Auth]

* The "kubectl api-resources" command will no longer fail to display any resources on a single failure  ([#73035](https://github.com/kubernetes/kubernetes/pull/73035), [@juanvallejo](https://github.com/juanvallejo))

## Urgent Upgrade Notes 

### (No, really, you MUST read this before you upgrade)