AWS Security ChangesHomeSearch

AWS AWSCloudFormation documentation change

Service: AWSCloudFormation · 2025-09-19 · Documentation low

File: AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-vpc.md

Summary

Clarified IPv4 CIDR block requirements for VPC creation

Security assessment

Routine documentation update about VPC configuration requirements with no security-specific changes.

Diff

diff --git a/AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-vpc.md b/AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-vpc.md
index 5e73e3cf1..b0fdf581e 100644
--- a//AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-vpc.md
+++ b//AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-vpc.md
@@ -11 +11 @@ Specifies a virtual private cloud (VPC).
-To add an IPv6 CIDR block to the VPC, see [AWS::EC2::VPCCidrBlock](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpccidrblock.html).
+A VPC must have an associated IPv4 CIDR block. You can specify an IPv4 CIDR block or an IPAM-allocated IPv4 CIDR block. To associate an IPv6 CIDR block with the VPC, see [AWS::EC2::VPCCidrBlock](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpccidrblock.html).