Users may be unable to access or may experience delays when accessing Microsoft Fabric

A post-incident report has been published.

A post-incident report has been published.

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may have been unable to access or may have experienced delays when accessing Microsoft Fabric. Final status: After a period of extended monitoring, we confirmed that the issue is resolved. Scope of impact: Any user attempting to access Microsoft Fabric may have been impacted. Start time: Monday, May 18, 2026, at 1:53 PM UTC End time: Monday, May 18, 2026, at 8:59 PM UTC Root cause: On May 18, 2026, Microsoft identified elevated fraudulent traffic volumes for the Microsoft Fabric service. This resulted in increased load on portions of the front-end infrastructure, leading to intermittent service degradation. The traffic exhibited characteristics outside of typical usage patterns, which contributed to resource saturation before mitigation controls were fully optimized, leading to increased request failures. Next steps: - For a more comprehensive list of next steps and actions, please refer to the Post Incident Report document. We'll provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: The service remains healthy at this time and we're continuing to monitor telemetry and assess overall service stability to determine whether any additional actions to fully resolve the issue may be required. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Root cause: An unexpected increase in request traffic is causing the portion of infrastructure that handles Microsoft Fabric access to operate in a suboptimal state, resulting in impact. Next update by: Wednesday, May 20, 2026, at 2:00 AM UTC

Our telemetry indicates service health remains healthy following our mitigating actions and we're continuing to monitor to ensure the issue is fully resolved. This quick update is designed to give the latest information on this issue.

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: We’ve applied the targeted mitigations to resolve the issues with residual traffic in all regions, and our telemetry shows service health is recovering. Some users have reported impact is remediated and we'll continue to monitor service health to ensure the issue is resolved for all users. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Preliminary root cause: An unexpected increase in request traffic is causing the portion of infrastructure that handles Microsoft Fabric access to operate in a suboptimal state, resulting in impact. Next update by: Monday, May 18, 2026, at 10:00 PM UTC

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: We’re continuing to see improvements in the regions where our fix is deployed, and we're applying additional targeted mitigations to resolve the issues with residual traffic, which is contributing to a slower recovery for some users. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Preliminary root cause: An unexpected increase in request traffic is causing the portion of infrastructure that handles Microsoft Fabric access to operate in a suboptimal state, resulting in impact. Next update by: Monday, May 18, 2026, at 9:30 PM UTC

We’re continuing to see improvements in the regions where our fix is deployed. We’ve identified some residual traffic which is slowing recovery in some regions and are investigating additional targeted mitigations. This quick update is designed to give the latest information on this issue.

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: We've completed our deployment of the fix to the West US region, and we're seeing service health recovering as a result of our actions. We've started expanding the fix deployment to additional regions and we'll provide an ETA for resolution once one becomes available. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Preliminary root cause: An unexpected increase in request traffic is causing the portion of infrastructure that handles Microsoft Fabric access to operate in a suboptimal state, resulting in impact. Next update by: Monday, May 18, 2026, at 8:30 PM UTC

We're applying the fix to balance the impacting request traffic to a subset of the affected infrastructure. Once deployed, we will validate it fully resolves impact before deploying more broadly. This quick update is designed to give the latest information on this issue.

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: We're working on balancing the impacting request traffic to recover service health while we continue to investigate the source of impact and identify any additional mitigating actions. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Next update by: Monday, May 18, 2026, at 7:30 PM UTC

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: We've identified an unexpected increase in request traffic that's causing the portion of infrastructure to operate in a suboptimal state. We're continuing to investigate the source of this traffic while we determine the most efficient method to remediate the impact. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Next update by: Monday, May 18, 2026, at 6:30 PM UTC

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: Our service health monitoring has alerted us to increased failures occurring when users attempt to access Microsoft Fabric. We're investigating the call requests to the portion of service infrastructure responsible for facilitating access to Microsoft Fabric to identify the source of the failures. Scope of impact: Any user attempting to access Microsoft Fabric may be impacted. Start time: Monday, May 18, 2026, at 12:24 PM UTC Next update by: Monday, May 18, 2026, at 4:30 PM UTC

Title: Users may be unable to access or may experience delays when accessing Microsoft Fabric User impact: Users may be unable to access or may experience delays when accessing Microsoft Fabric. Current status: We're investigating a potential issue with Microsoft Fabric and checking for impact to your organization. We'll provide an update within 30 minutes.