Microsoft Entra September 2026: Tenant Governance goes GA as the MemberOf deadline nears

Microsoft published its September 2026 Microsoft Entra roundup on September 1, covering four capabilities that reached general availability since August, three new public previews, and three change announcements. The post came from Yina Arenas, CVP and Chief Product Officer of Identity and Network Access.

The stated theme is governance in the age of AI: governing tenants, consolidating access reviews, and controlling the traffic AI agents generate. That framing is fair, but it buries the part with a clock attached. Two of the three change announcements carry dates, and one of them will quietly stop dynamic group membership from updating.

Microsoft Entra Tenant Governance is the largest of the four. It became generally available on August 10, 2026, and bundles four things: discovery of related tenants across the organization, least-privileged cross-tenant delegated administration, configuration baselines with continuous drift monitoring, and controlled creation of new tenants. Baselines span Microsoft Defender, Entra, Exchange Online, Intune, Purview, and Teams.

User-centric access reviews, or UAR, change how reviewers work. Instead of reviewing one resource at a time, a reviewer sees a single user's access across multiple resources in a catalog, covering Entra ID groups plus connected and disconnected applications.

Lifecycle Workflows gained a smaller but welcome addition: administrators can clone an existing workflow from the workflow list or from a card during workflow creation. The clone opens on the review and create page, so details, configuration, and tasks can be edited before it's created.

The fourth item is Microsoft Entra Resource Accounts for Teams devices. It replaces password-based sign-in for Teams Rooms, Teams Panels, and common area phones with hardware-protected, device-bound credentials.

Microsoft Entra Domain Services now synchronizes the Security Accounts Manager account name from the onPremisesSamAccountName attribute in Entra ID. Applications that depended on that attribute on premises can rely on it in Azure deployments backed by Entra DS. The behaviour is on by default for new managed domains and can be enabled on existing ones, and it's limited to Enterprise and Premium SKUs. Cloud-only users still fall back to mailNickname-based generation.

Entra Cloud Sync can now provision users, groups, and group memberships from Entra ID into on-premises Active Directory Domain Services. Cloud-native users, users whose source of authority was converted to the cloud, B2B guests, and security groups are all in scope. Microsoft Learn now documents the users-only and users-and-groups options as preview.

The third preview is the Global Secure Access MCP Firewall. Model Context Protocol is the open standard AI agents use to reach external tools, and the firewall adds discovery of shadow MCP servers, allow and block decisions at the level of individual servers, tools, resources, or prompts, and protocol-version and transport requirements. None of it requires changing MCP clients, hosts, or servers.

Three announcements sit at the end of the roundup, and they matter more than the feature list for anyone running a production tenant.

First, the built-in Security Administrator role gains identity response actions against non-privileged users: disabling and enabling accounts, revoking active sessions, and forcing password resets. Microsoft expects the rollout to finish by the end of September 2026. Existing governance and auditing controls still apply, but the practical effect is that a role many organizations hand out for triage can now perform containment.

Second, the public preview of the memberOf rule operator ends on November 3, 2026. Microsoft says a single memberOf rule can slow dynamic membership processing across an entire tenant, which is why it never left preview and won't.

Third, User.ReadBasic.All is being narrowed. The permission was returning app role assignments and license details, which Microsoft describes as unintended. Apps that need role assignment data should request User.Read.All; apps that need license data should request LicenseAssignment.Read.All. Microsoft frames the change as fixing a vulnerability and says it isn't a breaking change for apps using the permission as intended.

Nothing gets deleted on November 3. Affected dynamic membership groups, dynamic administrative units, and entitlement management auto-assignment policies stay exactly as they were and stop processing changes. Per Microsoft Learn, that leaves stale Teams and SharePoint access, Conditional Access targeting that no longer matches the org chart, group-based licensing that keeps assigning to leavers, and access package assignments that never expire.

The practical first step is inventory. Export dynamic membership groups from the Entra admin center and search the rules for memberOf. Then check dynamic administrative units and entitlement management auto-assignment policies separately, because they use the same operator and are easy to forget.

Replacement is the hard part. memberOf was the closest thing Entra ID had to nested groups, and Microsoft has said it's developing an alternative without naming one. In the interim the realistic options are attribute-based rules that reproduce the same population, assigned groups maintained by a provisioning process, or synchronized on-premises groups where an AD structure already exists.

Tenants that adopted memberOf despite its preview status are the most exposed, and there are many of them. The operator solved a real gap and stayed in preview for years, which made it easy to treat as stable.

Application owners are next. Any workload consented to User.ReadBasic.All that reads app role assignments or license data will lose that data. The fix is to identify those apps now, decide whether the data is genuinely needed, and request the narrower permission rather than reflexively granting User.Read.All everywhere.

MSPs sit on both sides of this update. The same multi-tenant estates that make memberOf audits tedious are the ones Tenant Governance is built for, and the governance relationship model now feeds Defender multi-tenant management, which is still in preview. Security operations teams should also confirm whether the expanded Security Administrator role has reached their tenants, then update runbooks that currently assume a second role is needed to disable an account.

The memberOf replacement is the open question. Microsoft acknowledges the scenarios the operator addressed and says work continues on something that scales, but there's no timeline and no name. Anyone planning group architecture this quarter should assume nothing arrives before November.

The MCP Firewall is worth tracking for a different reason. Related Global Secure Access MCP capabilities require TLS inspection on end-user devices, because MCP data sits inside the encrypted payload, and only remote MCP servers are visible to the service. Local MCP servers running on a workstation produce no network footprint to inspect. That shapes what the control can realistically enforce.

Finally, watch how quickly the expanded Security Administrator role appears in your own tenant. Rollout dates in monthly roundups describe intent, not delivery, and role permission changes are worth verifying rather than assuming.