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AWS AWSCloudFormation documentation change

Service: AWSCloudFormation · 2025-11-22 · Documentation medium

File: AWSCloudFormation/latest/TemplateReference/aws-properties-s3-bucket-serversideencryptionrule.md

Summary

Added BlockedEncryptionTypes property documentation for preventing SSE-C encrypted object uploads

Security assessment

Documents new security control feature to block SSE-C encryption but doesn't address specific vulnerabilities

Diff

diff --git a/AWSCloudFormation/latest/TemplateReference/aws-properties-s3-bucket-serversideencryptionrule.md b/AWSCloudFormation/latest/TemplateReference/aws-properties-s3-bucket-serversideencryptionrule.md
index ed3732a78..afbe9b780 100644
--- a//AWSCloudFormation/latest/TemplateReference/aws-properties-s3-bucket-serversideencryptionrule.md
+++ b//AWSCloudFormation/latest/TemplateReference/aws-properties-s3-bucket-serversideencryptionrule.md
@@ -27,0 +28 @@ To declare this entity in your CloudFormation template, use the following syntax
+      "BlockedEncryptionTypes" : [BlockedEncryptionTypes](./aws-properties-s3-bucket-blockedencryptiontypes.html),
@@ -35,0 +37,2 @@ To declare this entity in your CloudFormation template, use the following syntax
+      BlockedEncryptionTypes: 
+        [BlockedEncryptionTypes](./aws-properties-s3-bucket-blockedencryptiontypes.html)
@@ -42,0 +46,15 @@ To declare this entity in your CloudFormation template, use the following syntax
+`BlockedEncryptionTypes`
+    
+
+A bucket-level setting for Amazon S3 general purpose buckets used to prevent the upload of new objects encrypted with the specified server-side encryption type. For example, blocking an encryption type will block `PutObject`, `CopyObject`, `PostObject`, multipart upload, and replication requests to the bucket for objects with the specified encryption type. However, you can continue to read and list any pre-existing objects already encrypted with the specified encryption type. For more information, see [Blocking or unblocking SSE-C for a general purpose bucket](https://docs.aws.amazon.com/AmazonS3/latest/userguide/blocking-unblocking-s3-c-encryption-gpb.html).
+
+###### Note
+
+Currently, this parameter only supports blocking or unblocking server-side encryption with customer-provided keys (SSE-C). For more information about SSE-C, see [Using server-side encryption with customer-provided keys (SSE-C)](https://docs.aws.amazon.com/AmazonS3/latest/userguide/ServerSideEncryptionCustomerKeys.html).
+
+_Required_ : No
+
+ _Type_ : [BlockedEncryptionTypes](./aws-properties-s3-bucket-blockedencryptiontypes.html)
+
+ _Update requires_ : [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)
+