AWS Security ChangesHomeSearch

AWS opensearch-service medium security documentation change

Service: opensearch-service · 2026-05-16 · Security-related medium

File: opensearch-service/latest/developerguide/aurora-mysql.md

Summary

Added requirement that CIDR block must use /24 prefix length when attaching pipeline to VPC

Security assessment

Mandating /24 CIDR blocks limits network exposure by preventing excessively permissive network ranges, reducing potential attack vectors and network reconnaissance risks.

Diff

diff --git a/opensearch-service/latest/developerguide/aurora-mysql.md b/opensearch-service/latest/developerguide/aurora-mysql.md
index 7116dd449..d934aedcd 100644
--- a//opensearch-service/latest/developerguide/aurora-mysql.md
+++ b//opensearch-service/latest/developerguide/aurora-mysql.md
@@ -332 +332 @@ To use Amazon Aurora as a source, you need to configure VPC access for the pipel
-If you're using the AWS Management Console to create your pipeline, you must also attach your pipeline to your VPC in order to use Amazon Aurora as a source. To do so, find the **Network configuration** section, select the **Attach to VPC** checkbox, and choose your CIDR from one of the provided default options, or select your own. You can use any CIDR from a private address space as defined in the [RFC 1918 Best Current Practice](https://datatracker.ietf.org/doc/html/rfc1918).
+If you're using the AWS Management Console to create your pipeline, you must also attach your pipeline to your VPC in order to use Amazon Aurora as a source. To do so, find the **Network configuration** section, select the **Attach to VPC** checkbox, and choose your CIDR from one of the provided default options, or select your own. The CIDR block must use a /24 prefix length. You can use any /24 CIDR from a private address space as defined in the [RFC 1918 Best Current Practice](https://datatracker.ietf.org/doc/html/rfc1918).