Incident with Actions
This summary is created by Generative AI and may differ from the actual content.
Overview
On August 18, 2026, between 05:02 UTC and 11:30 UTC, customers were unable to run jobs on Actions Larger Runners and were unable to view or manage Actions Runners and Runner Groups through the GitHub UI and API. The root cause was an expired authentication certificate unique to the backend service. The certificate had been rotated in KeyVault, but the enablement step at runtime was paused to prevent recurrence of previous incidents. The issue was mitigated by completing the enablement of the new certificate in the backend system.
Impact
Customers unable to run jobs on Actions Larger Runners for 6 hours 28 minutes. Customers unable to view or manage Actions Runners and Runner Groups through GitHub UI and API during the same period.
Trigger
Expired authentication certificate that had been rotated in KeyVault but not enabled at runtime due to a pause on the enablement operation to prevent recurrence of previous incidents.
Detection
Customers reported impacted performance for GitHub services, which led to investigation of backend request failures for Actions Larger Runners and runner/runner group data access.
Resolution
Completed the enablement of the new certificate in the backend system to restore authentication functionality. Added additional monitoring for this and other certificates. Initiated replacement of the relevant service as part of availability and scale work to align authentication and secret management with patterns across all GitHub services.
Root Cause
Expired authentication certificate unique to the backend service. The certificate had been rotated in KeyVault, but the runtime enablement step was paused to prevent recurrence of previous incidents triggered by that operation, leaving the system with an expired certificate.