Microsoft SharePoint Online will migrate to a new CDN service, Microsoft Azure Front Door, starting June 2025 and completing by July 2025. Organizations should add the new domain `public-cdn.sharepointonline.com` to their allow list, avoid hardcoding CDN URLs, and continue allowing the old domain. No admin action is required before the rollout.
Applies to: SharePoint Online
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).