Critical: The October 2026 Windows security update is now available + 4 more E8 changes (Sun 25 Oct)

25 October 2026 · 10 changes that matter, 401 reviewed.

1. The October 2026 Windows security update is now available — October 2026 Windows security updates are released, addressing VPN, AVD, and Storage Spaces Direct issues. These updates include new auditing and policy controls for ReFS volumes on external storage, enhancing future security hardening. [Patch Operating Systems, Patch Applications]
2. Power Apps: Expand model access and Maker Studio availability for generative pages via GitHub — Power Apps makers can now connect GitHub accounts to access generative AI models for page design, expanding AI capabilities and availability to more regions. This introduces external model dependencies and potential data egress risks.
3. Power Apps: Use Power Platform connectors in generative pages — Power Apps generative pages can now integrate data from Power Platform connectors. This expands AI's access to organisational data, increasing potential for data exposure and misuse if not properly governed. [Restrict Administrative Privileges, Application Control]
4. Microsoft Purview Audit: AuditLogQuery API generally available and Search-UnifiedAuditLog retiring — Microsoft Purview Audit is replacing the legacy PowerShell cmdlet Search-UnifiedAuditLog with the new AuditLogQuery API. This improves scalability and reliability for audit log retrieval, with the old cmdlet retiring by October 2027. (act before 2027-10-15)
5. Microsoft Copilot (Microsoft 365): Sales Development Agent - Meeting scheduling — A new Copilot Sales Development Agent can autonomously schedule meetings with prospects, accessing seller calendars and sending invitations. This introduces new autonomous identity capabilities and potential data exposure risks.
6. Microsoft Copilot (Microsoft 365): Enable semantic model in Sales agent — Copilot's Sales Agent can now use a 'semantic model' to better understand CRM data. This improves its ability to interpret business language and answer complex questions, requiring admin configuration of data sources. [Restrict Administrative Privileges]
7. Power Apps: Use Dataverse custom APIs in generative pages — Power Apps generative pages can now call Dataverse custom APIs, enabling server-side business logic execution. This introduces new avenues for data manipulation and process automation, requiring careful security governance. [Restrict Administrative Privileges, Application Control]
8. Microsoft Copilot (Microsoft 365): Sales Development Agent is now available — A new autonomous Copilot agent for sales development is now available. This agent can independently research, qualify, and engage leads, introducing new risks related to data handling, access, and autonomous decision-making.
9. Dynamics 365 Business Central: Data mirroring to Microsoft Fabric — Dynamics 365 Business Central data can now be mirrored to Microsoft Fabric's OneLake. This centralises business data for analytics, increasing data exposure and requiring robust governance over sensitive information. [Restrict Administrative Privileges]
10. Microsoft Teams: Default meeting templates — Admins can now enforce default Teams meeting settings, including security options, for all users. This standardises meeting security posture, reducing manual configuration errors and ensuring consistent protection.

What we ignored

• Dynamics 365 Sales: Create pricing rules for attribute-based and volume-based pricing — This is a business feature, not relevant to security posture or controls.
• Dynamics 365 Sales: Create product rules to guide sellers to valid product configurations — This feature is a business process improvement, not a security control.
• Microsoft Edge: Simplified Energy Saver — This is a power management feature, not a security control.
• Dynamics 365 Field Service: Keep Project Staffing and Field Service Scheduling Aligned — Operational feature with no direct security relevance.
• Dynamics 365 Business Central: Expense Agent - Use Expense Manager role center — Functional UI update, no security relevance.