Microsoft is working through a search outage affecting several Microsoft 365 apps, after a software deployment overloaded the backend systems that power search.

• What it is: Search queries in Outlook (web and desktop), SharePoint Online and OneDrive have been failing or returning incomplete results since Monday 17 August.
• Who is affected: Some Microsoft 365 business and enterprise users globally, tracked under Microsoft reference MO1456424.
• What the risk is: This is a service reliability issue, not a security incident. Microsoft has confirmed it is not the result of a cyberattack.
• What to do: No action is required on your end. Microsoft has deployed a fix and is monitoring recovery. If search is still unreliable for your team, check the Microsoft 365 Admin Center for the latest status against reference MO1456424.

We are monitoring this issue and will update clients directly if it affects anything beyond search functionality.