Microsoft Defender for Endpoint
Endpoint protectionMicrosoft Defender Endpoint Releases
In brief
The documentation now lists Linux release 101.26091.0003, including updated release, engine, and signature versions. It also documents a libcurl 8.22.0 upgrade addressing CVE-2026-9546 and stronger quarantine authorization and path protections.
What Defender admins need to know
Administrators can use these details to identify the release and assess its security improvements on Linux endpoints.
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 |
|---|---|---|---|---|
| Linux | 101.26091.0003 | October 2026 | - Release version: 30.126091.0003.0- Engine version: 1.1.26090.3000- Signature version: 1.461.35.0 | Release details and updates |
| 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 |
- Intermittent issue during process scanning: In version
101.26072.0004,wdavdaemonmight restart in rare cases while scanning running processes. The process recovers automatically, and no action is required. A fix will be available in an upcoming release. Resolution: Upgrade to platform version 101.26072.0005 or later.
Linux | October 2026 | 101.26091.0003
Release details
| Release version | Engine version | Signature version |
|---|---|---|
| 30.126091.0003.0 | 1.1.26090.3000 | 1.461.35.0 |
Enhancements and features
| Feature area | Update summary |
|---|---|
| Security | Upgraded libcurl to version 8.22.0 to address CVE-2026-9546. |
| Security | Hardened quarantine operations by enforcing authorization checks and protecting against file-path manipulation that could lead to privilege escalation. |
Linux | September 2026 | 101.26081.0010
Release details
@@ -11,8 +11,8 @@ manager: bagol description: Find release details for Microsoft Defender for Endpoint on Windows, macOS, Linux, Android, and iOS from the past six months. ms.topic: whats-new ms.service: defender-endpoint-author: lwainstein-ms.author: lwainstein+author: abhisheksh+ms.author: abhisheksh ms.reviewer: noamhadash, pahuijbr, yongrhee ms.localizationpriority: medium ms.date: 2026-10-12T00:00:00.0000000Z@@ -59,6 +59,7 @@ This table includes supported releases for all supported platforms in the past s
| OS | Build | Month released | Details | Learn more |
| --- | --- | --- | --- | --- |
+| Linux | 101.26091.0003 | October 2026 | - Release version: 30.126091.0003.0- Engine version: 1.1.26090.3000- Signature version: 1.461.35.0 | Release details and updates |
| 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 |
@@ -610,6 +611,21 @@ If you have any concerns or need assistance during this transition, contact supp
- **Intermittent issue during process scanning**: In version `101.26072.0004`, `wdavdaemon` might restart in rare cases while scanning running processes. The process recovers automatically, and no action is required. A fix will be available in an upcoming release. **Resolution**: Upgrade to platform version 101.26072.0005 or later.
+### Linux | October 2026 | 101.26091.0003
+
+#### Release details
+
+| Release version | Engine version | Signature version |
+| --- | --- | --- |
+| 30.126091.0003.0 | 1.1.26090.3000 | 1.461.35.0 |
+
+#### Enhancements and features
+
+| Feature area | Update summary |
+| --- | --- |
+| Security | Upgraded libcurl to version 8.22.0 to address CVE-2026-9546. |
+| Security | Hardened quarantine operations by enforcing authorization checks and protecting against file-path manipulation that could lead to privilege escalation. |
+
### Linux | September 2026 | 101.26081.0010
#### Release details