Microsoft Defender has expanded Unified role-based access control (URBAC) permissions for email content access to include alerts related to potentially malicious URL clicks. Security analysts with the appropriate permission can now preview and download emails from four alert types, ensuring consistent access across scenarios.
Today in Microsoft Defender
Every tracked change across Microsoft Defender documentation, in plain English. Browse the archive from 1 January 2026 → About this project →
Day in brief
Microsoft Entra Security Operator loses default threat-policy and Tenant Allow/Block List access in December
Starting in December 2026, Microsoft Defender for Office 365 will update Unified RBAC mapping for the Microsoft Entra Security Operator role, removing default access to email threat policies and the Tenant Allow/Block List. A separate URBAC expansion adds email preview and download access for alerts involving potentially malicious URL clicks. Endpoint guidance also sharpens local AI-agent discovery limits and prerequisites, while Sentinel guidance documents MCP-assisted triage querying.
- Security Operator RBAC mapping will remove default email-policy access
Defender XDR · Email and collaborationMicrosoft Defender for Office 365 will update the Unified RBAC mapping for the Microsoft Entra Security Operator role beginning in December 2026. Default access to email threat policies and the Tenant Allow/Block List will be removed, so organizations needing continued access must manually assign permissions.
- URBAC email-content access expands to malicious URL-click alerts
Defender XDR · GeneralMicrosoft Defender now includes alerts related to potentially malicious URL clicks in its expanded email-content permission support. Analysts with the appropriate permission can preview and download emails from four alert types.
- Local-agent inventory guidance clarifies what discovery proves
Endpoint · Endpoint protectionThe Defender for Endpoint guidance states that observing an agent process can create an inventory entry without a prompt or service permission, and that discovery does not prove active use or successful access. It also adds minimum Defender versions and Unified RBAC permissions for viewing inventory and the attack surface graph.
- MCP server discovery now has explicit endpoint prerequisitesEndpoint · Endpoint protection
The Local Agent Discovery Overview distinguishes process-based discovery from VS Code extension collection on Windows and macOS. It states that MCP server configuration discovery requires antivirus active mode and real-time protection, and removes the macOS preview note from the guidance.
- Sentinel guidance documents MCP-based triage collection
Sentinel · Cloud and workloadsThe Sentinel What's New guidance now describes using the Sentinel MCP triage collection to discover data, list available Advanced Hunting tables, and run hunting queries in the built-in data lake.
This period briefing was generated by AI from the tracked Microsoft Learn and Message Center changes.
11 updates
Microsoft Defender XDR
4 updatesAi Agent Inventory
Feature updateThe documentation now separates cloud-agent enablement from local-agent discovery. Local agents have separate onboarding and no longer require AI agent runtime protection for discovery.
Microsoft is updating the Microsoft Defender for Office 365 Unified RBAC mapping for the Microsoft Entra Security Operator role, removing default access to email threat policies and Tenant Allow/Block List. Rollout starts December 2026. Organizations must manually assign permissions if continued access is needed.
Get Started Defender Security For Ai
Feature updateThe setup guidance now separates local and cloud agent onboarding. Local agent discovery follows separate prerequisites and does not require AI agent runtime protection; runtime protection can be configured independently.
Microsoft Defender for Endpoint
5 updatesAi Agent Support Matrix
Generally availableThe documentation now covers local AI agent discovery on supported Windows and macOS devices, with specific preview exceptions. It updates discovery details, adds Microsoft VS Code extensions, revises MCP coverage, and expands macOS entries with preview indicators.
Local Agent Discovery Overview
Feature updateAction requiredThe documentation now distinguishes process-based discovery from VS Code extension collection on Windows and macOS. It also states that MCP server configuration discovery requires antivirus active mode and real-time protection, and removes the macOS preview note.
Discover local AI agents with Microsoft Defender for Endpoint - Microsoft Defender for Endpoint | Microsoft Learn
Feature updateAction requiredThe documentation now states that observing an agent process can create an inventory entry without a prompt or service permission, and that discovery does not prove active use or successful access. It adds minimum Defender versions and unified RBAC permissions for viewing inventory and the attack surface graph.
Microsoft Defender Endpoint Releases
Doc updateThe release notes now document Linux version 101.26101.0000, including an OpenSSL 3.6.4 upgrade and a fix for missing CentOS minor patch versions in the Defender portal.
Whats New In Microsoft Defender Endpoint
Generally availableThe documentation now describes local AI agent discovery on onboarded Windows and macOS devices, including discovery of configured MCP servers and investigation through the AI agent inventory and advanced hunting.
Mdo Email Entity Page
Doc updateUpdated author metadata and revised the ZAP example to state that a message moved to quarantine expires from quarantine.
Microsoft Sentinel
1 updateWhats New
New featureThe Microsoft Sentinel What's New page now describes using the Sentinel MCP triage collection to discover data, list available Advanced Hunting tables, and run hunting queries in the built-in data lake.