Microsoft Defender for Endpoint
Endpoint protectionMicrosoft Defender Endpoint Releases
In brief
The documentation adds Platform 4.18.26090.9, Engine 1.1.26090.9, and security intelligence 1.461.1.0 release details, including automatic protection-engine refresh, improved update reliability, ASR path handling, and policy-exclusion retention.
What Defender admins need to know
Review automation using the renamed PowerShell property, ConfigurationProtection, and account for the updated protection and ASR behavior when validating deployments.
Summaries are generated from the documentation change itself.
Documentation change
View on Microsoft LearnThe comparison below shows only the changed extract. Use the full-page view for complete context.
| OS | Build | Month released | Details | Learn more |
|---|---|---|---|---|
| Windows Antivirus | Platform 4.18.26090.9 / Engine 1.1.26090.9 | September 2026 | - Platform: 4.18.26090.9- Engine: 1.1.26090.9- Security intelligence: 1.461.1.0 | Release details and updates |
| Windows Antivirus | Platform 4.18.26080.4 / Engine 1.1.26080.3 | August 2026 | - Platform: 4.18.26080.4- Engine: 1.1.26080.3- Security intelligence: 1.159.11.0 | Release details and updates |
| Android | 1.0.9330.0101 | Sep 2026 | - Build: 1.0.9330.0101- Release: Sep 30, 2026 | Release details and updates |
| iOS | 1.1.81160103 | Sep 2026 | - Build: 1.1.81160103- Release: Sep 24, 2026 | Release details and updates |
For more information about Microsoft Defender Antivirus updates, see Microsoft Defender Antivirus security intelligence product updates and support.
Windows Antivirus | September 2026 | Platform 4.18.26090.9 | Engine 1.1.26090.9
Release details
| Component | Version | Date |
|---|---|---|
| Platform | 4.18.26090.9 | October 12, 2026 |
| Engine | 1.1.26090.9 | October 12, 2026 |
| Security intelligence^1^ | 1.461.1.0 | October 12, 2026 |
| Support phase | Security and Critical Updates | - |
^1^The security intelligence version listed here is relevant to the listed engine release. Newer versions of security intelligence are released regularly. For more information, see Security intelligence updates for Microsoft Defender Antivirus and other Microsoft anti-malware.
Enhancements and features
- Added automatic protection-engine refresh when the device's resolved license tier changes.
- Fixed a stalled security-intelligence update worker which could block all subsequent updates.
- Addressed an update configuration issue that could leave DisableBmNetworkSensor = 1 after platform updates.
- Renamed the PowerShell configuration-protection property from ControlledConfigurationState to ConfigurationProtection.
- Retained the feature-control cache during signature updates to preserve cached settings through the update lifecycle.
- Improved path-normalization handling for Attack Surface Reduction rules.
- Fixed attack surface reduction exclusions being dropped when multiple policies target the same rule.
Windows Antivirus | August 2026-2 | Platform 4.18.26080.4 | Engine 1.1.26080.3
Release details
@@ -15,7 +15,7 @@ author: lwainstein ms.author: lwainstein ms.reviewer: noamhadash, pahuijbr, yongrhee ms.localizationpriority: medium-ms.date: 2026-09-25T00:00:00.0000000Z+ms.date: 2026-10-12T00:00:00.0000000Z ai-usage: ai-assisted locale: en-us document_id: a82695da-2a19-ab7b-fd85-324ba1ae897f@@ -59,6 +59,7 @@ This table includes supported releases for all supported platforms in the past s
| OS | Build | Month released | Details | Learn more |
| --- | --- | --- | --- | --- |
+| Windows Antivirus | Platform 4.18.26090.9 / Engine 1.1.26090.9 | September 2026 | - Platform: 4.18.26090.9- Engine: 1.1.26090.9- Security intelligence: 1.461.1.0 | Release details and updates |
| Windows Antivirus | Platform 4.18.26080.4 / Engine 1.1.26080.3 | August 2026 | - Platform: 4.18.26080.4- Engine: 1.1.26080.3- Security intelligence: 1.159.11.0 | Release details and updates |
| Android | 1.0.9330.0101 | Sep 2026 | - Build: 1.0.9330.0101- Release: Sep 30, 2026 | Release details and updates |
| iOS | 1.1.81160103 | Sep 2026 | - Build: 1.1.81160103- Release: Sep 24, 2026 | Release details and updates |
@@ -1449,6 +1450,29 @@ For the latest UX improvements, see [iOS UX improvements](ios-new-ux).
For more information about Microsoft Defender Antivirus updates, see [Microsoft Defender Antivirus security intelligence product updates and support](microsoft-defender-antivirus-updates).
+### Windows Antivirus | September 2026 | Platform 4.18.26090.9 | Engine 1.1.26090.9
+
+#### Release details
+
+| Component | Version | Date |
+| --- | --- | --- |
+| Platform | 4.18.26090.9 | October 12, 2026 |
+| Engine | 1.1.26090.9 | October 12, 2026 |
+| Security intelligence^1^ | 1.461.1.0 | October 12, 2026 |
+| Support phase | Security and Critical Updates | - |
+
+^1^The security intelligence version listed here is relevant to the listed engine release. Newer versions of security intelligence are released regularly. For more information, see [Security intelligence updates for Microsoft Defender Antivirus and other Microsoft anti-malware](https://www.microsoft.com/wdsi/defenderupdates).
+
+### Enhancements and features
+
+- Added automatic protection-engine refresh when the device's resolved license tier changes.
+- Fixed a stalled security-intelligence update worker which could block all subsequent updates.
+- Addressed an update configuration issue that could leave DisableBmNetworkSensor = 1 after platform updates.
+- Renamed the PowerShell configuration-protection property from ControlledConfigurationState to ConfigurationProtection.
+- Retained the feature-control cache during signature updates to preserve cached settings through the update lifecycle.
+- Improved path-normalization handling for Attack Surface Reduction rules.
+- Fixed attack surface reduction exclusions being dropped when multiple policies target the same rule.
+
### Windows Antivirus | August 2026-2 | Platform 4.18.26080.4 | Engine 1.1.26080.3
#### Release details