Active – Customers leveraging a subset of services may experience 401 authentication errors

Update timeline

1. monitoring Jun 15, 2026, 11:44 PM UTC

   Impact Statement: Starting at 21:45 UTC on 15 June 2026, a subset of Azure customers leveraging services which depend upon MCR (Microsoft Container Registry) for storing images may experience 401 authentication errors for requests attempting to pull Microsoft images from mcr.microsoft.com.Current Status: We detected this issue via internal service monitoring upon identifying a spike of 401 errors. We’ve identified a potential underlying factor to be a recent update which introduced a code regression, and we've completed roll out of a hotfix to address the code regression and mitigate impact for affected customers. We are closely monitoring internal telemetry to validate full mitigation and prevent further occurrences. The next update will be provided within 60 minutes, or as events warrant.