Merge pull request #5132 from MicrosoftDocs/poliveria-whats-new-09262025

Add September 2025 updates to what's new

Author: poliveria

defender-xdr/whats-new.md

@@ -32,6 +32,10 @@ For more information on what's new with other Microsoft Defender security produc
 
 You can also get product updates and important notifications through the [message center](https://admin.microsoft.com/Adminportal/Home#/MessageCenter).
 
+## September 2025
+- (Preview) You can investigate incidents using [Blast radius analysis](investigate-incidents.md#blast-radius-analysis), which is an advanced graph visualization built on the Microsoft Sentinel data lake and graph infrastructure. This feature generates an interactive graph showing possible propagation paths from the selected node to predefined critical targets scoped to the user’s permissions.
+- (Preview) In advanced hunting, you can now hunt using the [hunting graph](advanced-hunting-graph.md), which renders rendering predefined threat scenarios as interactive graphs.
+
 ## August 2025
 
 - (Preview) In advanced hunting, you can now enrich your [custom detection rules](custom-detection-rules.md) by creating dynamic alert titles and descriptions, select more impacted entities, and add custom details to display in the alert side panel. Microsoft Sentinel customers that are onboarded to Microsoft Defender also now have the option to customize the alert frequency when the rule is based only on data that is ingested to Sentinel.