Changes / GitHub Copilot / Disruption with Login and Release Asset downloads
GitHub Copilot: Major incident: Disruption with Login and Release Asset downloads
Summary
GitHub reported a major disruption affecting login pages and Release Asset downloads, starting 2026-08-12 21:39 UTC and resolved at 2026-08-12 22:56 UTC (1 h 17 min). Some logged-out requests received HTTP 5xx errors because an unusual traffic pattern repeatedly overloaded infrastructure serving those requests.
Machine-written from the diff below (Sol; type: incident outage). Check the diff before relying on it.
What changed
Before: not present
After: Disruption with Login and Release Asset downloads
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After: major
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After: resolved
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After: 2026-08-12 21:39 UTC
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After: 2026-08-12 22:56 UTC
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After: We are investigating reports of impacted performance for some GitHub services.
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After: We are investigating issues with Login and when downloading Release Assets. We will continue to keep users updated on progress towards mitigation.
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After: We have identified the root cause and are working on mitigation. Errors on the login page and downloading release assets have decreased, but we are not fully mitigated. We will continue to provide updates.
Before: not present
After: On August 12 and 13, 2026, some anonymous (logged-out) requests to github.com experienced HTTP 5xx errors when loading pages like the sign-in page, and when downloading release assets, due to an unusual traffic pattern that repeatedly overloaded a part of our infrastructure that serves these types of requests. There were three windows of impact: (1) August 12 from 16:34 to 18:34 UTC, with an average error rate of 16.16% that peaked at 28.6%; (2) August 12 from 19:00 to 22:56 UTC, with an average error rate of 16.55% that peaked at 24.18%; and (3) August 13 from 06:19 to 08:05 UTC, with an average error rate of 2.01% that peaked at 7.49%.<br />Requests from signed-in users were unaffected.<br /><br />We mitigated the incidents by applying traffic controls at our network edge that limited any requests matching the pattern identified previously, thereby preventing overload on our systems.<br /><br />Since these incidents occurred, we have tightened our monitoring systems to alert server-side errors that affect logged-out traffic. We are also working to further strengthen our edge protections and reduce the time to detect and mitigate similar incidents.
First version of this incident archived by Rewindex. View the live incident.
History of this incident
| When (UTC) | Change | Kind |
|---|---|---|
| Major incident: Disruption with Login and Release Asset downloads (this change) GitHub reported a major disruption affecting login pages and Release Asset downloads, starting 2026-08-12 21:39 UTC and resolved at 2026-08-12 22:56 UTC (1 h 17 min). Some logged-out requests received HTTP 5xx errors because an unusual traffic pattern repeatedly overloaded infrastructure serving those requests. | Major incident |
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