On June 10, 2026 GitHub experienced a brief outage that degraded its API Requests and Issues endpoints. Roughly 15% of API traffic returned erroneous 401 responses, forcing client applications to re‑authenticate. The incident triggered alerts across third‑party integrations that rely on continuous authentication tokens. GitHub posted hourly updates as engineers traced the problem across its global data centers during peak usage.

Investigators identified a faulty load‑balancer configuration in the authentication layer as the root cause. The misrouting caused the service to drop valid credentials, producing the 401 errors. Because many CI/CD pipelines poll the API continuously, the glitch introduced cascading build failures and delayed deployments for teams worldwide. Engineers rolled back the configuration and verified restored token validation for affected developers and organizations.

By 16:39 UTC GitHub declared the degradation mitigated and entered a monitoring phase to ensure stability. No further 401 responses have been observed, and normal request latency has returned. The rapid response limited customer impact and demonstrated the platform’s incident‑response procedures. GitHub will publish a full root‑cause analysis once the post‑mortem concludes as part of continuous improvement.