Disruption with some GitHub services
Final update
On May 26, 2026, between 15:10 UTC and 16:35 UTC the Copilot service was degraded and many models were no longer available for use. On average, the error rate was ~5% and peaked at 11% of requests to the service. This was due to a change that introduced a configuration mismatch in HMAC signing credentials which caused the list of available models to be truncated. This was mitigated by rolling back the change. This rollback was complete by 15:34 UTC though users continued to see impact until cache TTLs expired. We are working to improve our monitoring and error handling to reduce time to detection and better experience for issues like this in the future.
Timeline
- Resolved · May 26, 16:35 UTC
On May 26, 2026, between 15:10 UTC and 16:35 UTC the Copilot service was degraded and many models were no longer available for use. On average, the error rate was ~5% and peaked at 11% of requests to the service. This was due to a change that introduced a configuration mismatch in HMAC signing credentials which caused the list of available models to be truncated. This was mitigated by rolling back the change. This rollback was complete by 15:34 UTC though users continued to see impact until cache TTLs expired. We are working to improve our monitoring and error handling to reduce time to detection and better experience for issues like this in the future.
More from GitHub
Full history| Started | Incident | Impact | Duration |
|---|---|---|---|
| Sep 2416:51 UTC | Disruption with billing information updates | minor | 3h 50m |
| Sep 2310:11 UTC | Incident across several services | minor | 18h 44m |
| Sep 2022:13 UTC | Incident with Pull Requests | minor | 1h 9m |
| Sep 1720:59 UTC | Elevated rate of errors for OpenAI models provided by Copilot | minor | 50m |
| Sep 1607:20 UTC | Degradation with Gemini 3.8 Flash | major | 10h 28m |
| Sep 1519:11 UTC | Disruption with some GitHub services | minor | 49m |
Sources: vendors' own status pages, published postmortems and SEC 8-K Item 1.05 filings, read daily. Times as reported. Logos via logo.dev; trademarks belong to their owners.