ARCHIVED OFFICIAL INCIDENT

Incident with GitHub.com

GitHub · Last saved provider status: resolved

Current service report →
This is historical evidence.

The last saved event status is not the current service status. Source lists can be incomplete, and disappearance from a source does not confirm recovery. Open the current report or the official source for newer evidence.

Saved event details

Provider status
resolved
Provider impact
critical
Provider record created
17 Aug 2026, 13:40:03 UTC
Provider record updated
18 Aug 2026, 19:21:36 UTC
Explicit provider start
17 Aug 2026, 13:40:03 UTC
Explicit provider end
17 Aug 2026, 21:15:46 UTC

Affected components reported by the provider

  • Webhooks 4230lsnqdsld
  • Git Operations 8l4ygp009s5s
  • Actions br0l2tvcx85d
  • API Requests brv1bkgrwx7q
  • Pull Requests hhtssxt0f5v2
  • Issues kr09ddfgbfsf
  • Copilot pjmpxvq2cmr2
  • Pages vg70hn9s2tyj

These associations describe this event’s reported scope. They do not establish current component availability or verified dependencies.

A record creation time is not necessarily an outage start. Unreported times remain unavailable. We do not calculate downtime from collection times.

Provider updates in saved revisions

Latest first. We show up to 100 distinct updates from the latest 20 saved content revisions. Revised wording at the same provider time is retained separately.

  1. resolved

    On August 17, 2026, from 13:28–21:15 UTC (7h 47m), GitHub.com experienced elevated errors and latency across Issues, Pull Requests, APIs, Actions, and Copilot. At peak, web/API error rates were approximately 20%, while archive and raw-content downloads reached approximately 50%. SAML/OIDC authentication, SCIM, and Team Sync were also affected, as well as Actions workflows in GHEC with Data Residency that depend on public workflow step definitions hosted on GitHub.com. Most services recovered by 16:36 UTC as our Central US datacenter recovered; Actions was degraded until approximately 18:03 UTC; and Copilot Token Service fully recovered by 21:02. <br /><br />Some of the failing traffic was moved from Central US to Northern Virginia where it was served successfully until the network failure in Central US was debugged and resolved. Delayed replies to a single internal endpoint triggered a latent retry bug in VS Code that amplified traffic by approximately 10x and caused delayed recovery for the Copilot Token Service. <br /><br />The immediate cause of the failure was network saturation on load balancers in Central US due to a new peak in traffic. Originally this was caused by an Istio sidecar pod reaching its concurrency limits and failing to auto scale correctly because of a misconfigured policy that watched host service but not sidecar limits. One failure cascaded to more and eventually four HAProxy nodes exhausted their flow limits, degrading the gateway auth path and causing widespread authentication latency and failures. The problem was worsened by optimistic retry logic which overloaded internal load balancers. Pausing HAProxy on those nodes simultaneously produced immediate broad recovery. <br /><br />The retry storm in Northern VA was fixed by 1) temporarily reducing gateway retry logic with a PR and 2) blocking inbound Copilot Token Service token requests at the load balancers with a 403, and then gradually ramping back up traffic per-site to allow callers to succeed. <br /><br />Residual Copilot authentication failures continued because client retry behavior amplified load: a failed token operation could generate many extra requests and enter a retry loop. Copilot Token Service traffic increased from a normal 7–9K RPS to 70–100K RPS. Reducing gateway authentication retries and blocking retry-triggering responses stabilized Copilot Token Service and completed recovery. <br /><br />Complicating factors that impeded recovery included a number of scraping attacks on codeload endpoints. <br /><br />To prevent recurrence, our follow-up actions include: <br /><br />- Correcting autoscaling policies to account for service-mesh sidecar concurrency and capacity. <br /><br />- Auditing Istio request, concurrency, and scaling limits across affected services. <br /><br />- Reviewing retry limits and backoff behavior across gateways and clients. <br /><br />- Addressing the VS Code retry behavior that amplified Copilot token traffic. <br /><br />- Improving load-balancer capacity monitoring and regional failover safeguards.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  2. investigating

    We are continuing to apply mitigations to address sporadic Copilot authentication failures in some applications. We expect full recovery within the next 30 minutes. Copilot usage via the GitHub CLI and GitHub App are unaffected.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  3. investigating

    Issues is operating normally.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  4. investigating

    We are continuing to investigate sporadic failures affecting Copilot authentication in some applications. Copilot usage via the GitHub CLI and GitHub App are unaffected.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  5. investigating

    We are continuing to investigate sporadic authentication failures. We have partially disabled authentication token retries and have seen improvement, and we are monitoring impact before fully applying this mitigation.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  6. investigating

    API Requests is operating normally.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  7. investigating

    API Requests is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  8. investigating

    The degradation affecting Git Operations has been mitigated. We are monitoring to ensure stability.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  9. investigating

    We identified the problematic component and have taken corrective actions, but we are seeing residual impact in the form of sporadic authentication failures. We are continuing to apply additional mitigations and investigate the remaining impact.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  10. investigating

    Issues is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  11. investigating

    We identified the problematic component and have taken corrective actions, but we are seeing residual impact across numerous services. We are continuing to apply additional mitigations and investigate the remaining impact.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  12. investigating

    Git Operations is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  13. investigating

    The degradation affecting API Requests, Actions, Git Operations, Issues, Pages, Pull Requests and Webhooks has been mitigated. We are monitoring to ensure stability.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  14. investigating

    We identified the problematic component and have taken corrective actions. There are strong signs of recovery but we are still working to completely restore service, with error rates still remaining slightly elevated. We will post further updates as recovery continues.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  15. investigating

    We are experiencing high error rates around 20% for web experiences and api traffic. Archive downloads and raw repository content downloads are experiencing an approximate 50% error rate. SAML and OIDC authentication, SCIM, and Team Sync are also impacted. We are still working to identify the root cause and will continue to post updates as we learn more and perform mitigation.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  16. investigating

    We are experiencing high error rates around 20% for web experiences and api traffic. Archive downloads and raw repository content downloads are experiencing an approximate 50% error rate. SAML and OIDC authentication, SCIM, and Team Sync are also impacted. We are currently performing mitigations and will post updates as we progress.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  17. investigating

    Webhooks is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  18. investigating

    Git Operations is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  19. investigating

    Pages is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  20. investigating

    API Requests is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  21. investigating

    Webhooks is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  22. investigating

    We are experiencing high error rates around 20% for web experiences and api traffic. Archive downloads and raw repository content downloads are experiencing an approximate 50% error rate. SAML and OIDC authentication, SCIM, and Team Sync are also impacted. We are currently performing mitigations based on our investigation thus far and are monitoring for improvement.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  23. investigating

    Actions is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  24. investigating

    Pull Requests is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  25. investigating

    Issues is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  26. investigating

    Pull Requests is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  27. investigating

    Copilot is experiencing degraded availability. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  28. investigating

    We are experiencing high error rates around 20% for web experiences and api traffic. Archive downloads and raw repository content downloads are experiencing an approximate 50% error rate. SAML and OIDC authentication, SCIM, and Team Sync are also impacted. Investigations are on-going and we will continue to provide updates as we discover more information.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  29. investigating

    We are experiencing high error rates around 20% for web experiences and api traffic. Archive downloads and raw repository content downloads are experiencing an approximate 50% error rate. Investigations are on-going into the root cause, and updates will continue to be provided as we investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  30. investigating

    Pull Requests is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  31. investigating

    Issues is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  32. investigating

    We are seeing an approximate 20% error rate across numerous experiences including Pull Requests, Issues, and others. Investigations are currently under way and we will be posting updates as they become available

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  33. investigating

    Webhooks is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  34. investigating

    Actions is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  35. investigating

    API Requests is experiencing degraded performance. We are continuing to investigate.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC
  36. investigating

    We are investigating reports of impacted performance for some GitHub services.

    Seen in a saved revision at 06 Oct 2026, 13:58:39 UTC