website/content/en/docs/reference/command-line-tools-reference/feature-gates/StrictIPCIDRValidation.md

title	content_type	_build	stages
StrictIPCIDRValidation	feature_gate	list render never false	stage defaultValue fromVersion alpha false 1.33

Use stricter validation for fields containing IP addresses and CIDR values.

In particular, with this feature gate enabled, octets within IPv4 addresses are not allowed to have any leading 0s, and IPv4-mapped IPv6 values (e.g. ::ffff:192.168.0.1) are forbidden. These sorts of values can potentially cause security problems when different components interpret the same string as referring to different IP addresses (as in CVE-2021-29923).

This tightening applies only to fields in build-in API kinds, and not to custom resource kinds, values in Kubernetes configuration files, or command-line arguments.