- Since golang 1.17 both net.ParseIP and net.ParseCIDR rejects leading zeros in the dot-decimal notation of IPv4 addresses,
  Kubernetes will keep allowing leading zeros on IPv4 address to not break the compatibility.
  IMPORTANT: Kubernetes interprets leading zeros on IPv4 addresses as decimal, users must not rely on parser alignment to not being impacted by the associated security advisory:

## Changelog since v1.17.7

## Changes by Kind

### API Change

- Fixed: log timestamps now include trailing zeros to maintain a fixed width ([#91207](https://github.com/kubernetes/kubernetes/pull/91207), [@iamchuckss](https://github.com/iamchuckss)) [SIG Apps and Node]

### Bug or Regression

## Changelog since v1.18.4

## Changes by Kind

### API Change

- Fixed: log timestamps now include trailing zeros to maintain a fixed width ([#91207](https://github.com/kubernetes/kubernetes/pull/91207), [@iamchuckss](https://github.com/iamchuckss)) [SIG Apps and Node]

### Bug or Regression

- Added warnings to the Services API. Kubernetes now warns for Services in the case of:
  - IPv4 addresses with leading zeros
  - IPv6 address in non-canonical format (RFC 5952) ([#114505](https://github.com/kubernetes/kubernetes/pull/114505), [@aojea](https://github.com/aojea))

* When HPAScaleToZero feature gate is enabled HPA supports scaling to zero pods based on object or external metrics. HPA remains active as long as at least one metric value available. ([#74526](https://github.com/kubernetes/kubernetes/pull/74526), [@DXist](https://github.com/DXist))
    * To downgrade the cluster to version that does not support scale-to-zero feature:

- Removed leading zeros from the etcd member ID in kubeadm log messages. ([#117919](https://github.com/kubernetes/kubernetes/pull/117919), [@dlipovetsky](https://github.com/dlipovetsky)) [SIG Cluster Lifecycle]

- The apiserver will now return warnings if you create objects with "invalid" IP or
  CIDR values (like "192.168.000.005", which should not have the extra zeros).
  Values with non-standard formats can introduce security problems, and will

- Added an e2e test to verify that the cluster is not vulnerable to CVE-2021-29923 when using Services with IPs with leading zeros, note that this test is a necessary but not sufficient condition, all the components in the clusters that consume IPs addresses from the APIs MUST interpret them as decimal or discard them. ([#107552](https://github.com/kubernetes/kubernetes/pull/107552),...

precision without overflow. Rounding uses IEEE 754 round-to-even rules but with an IEEE
negative zero further simplified to an unsigned zero. Note that constant values never result
in an IEEE negative zero, NaN, or infinity.
</li>

<li>
<code>T</code> is a complex type, and <code>x</code>'s

- `VolumeBindingArgs` now allow `BindTimeoutSeconds` to be set as zero, while the value zero indicates no waiting for the checking of volume binding operation. ([#99835](https://github.com/kubernetes/kubernetes/pull/99835), [@chendave](https://github.com/chendave)) [SIG Scheduling and Storage]