Azure Sphere May update brings tighter security and control for Legacy access

Microsoft has released the May 2025 update for Azure Sphere, focusing on security and migration tools, but no OS or SDK changes this time. The update introduces new features to manage Legacy access, expired certificates, and device security more tightly.

May 2025 update brings new controls for Azure Sphere (Legacy) access

You can now pause or re-enable Azure Sphere (Legacy) access directly from the Azure portal. This helps organizations verify that no Legacy services are still in use during migration to Azure Sphere (Integrated), which replaces Legacy completely on September 27, 2027.

• Once paused, any attempt to use Legacy triggers an error, making it easy to spot forgotten use cases.
• You can temporarily re-enable Legacy if migration isn’t fully complete.
• New Azure Sphere catalogs now pause Legacy access by default unless they’re created from existing Legacy tenants.

Azure Sphere May 2025 update restricts expired certificate downloads

It should be noted that expired catalog or tenant certificates can no longer be downloaded. While this change doesn’t affect live environments, since expired certificates are already unusable, it improves security posture. Metadata for expired certs is still visible, but download attempts via CLI or portal will return “null” or “not found.”

Option to block device certificates via support

Admins can now request to block individual devices from receiving Azure Sphere-issued certificates. This is useful for lost, stolen, or retired devices. Blocked devices will no longer be trusted by services like Azure IoT Hub. To use this feature, contact [email protected].