Pull Requests and Issues unavailable for signed-out users

What happened

On June 8, 2026, between approximately 06:30 UTC and 08:36 UTC, signed-out users experienced sustained elevated HTTP 504 errors when accessing Pull Requests, Issues, releases, patch diffs, and other related GitHub.com pages. During the incident, approximately 17% of unauthenticated requests to the affected GitHub.com endpoints returned gateway timeout errors, peaking at roughly 34% of requests at around 06:50 UTC. Some GitHub Actions workflows were also affected when they depended on release downloads or related GitHub.com endpoints. The impact lasted approximately two hours and was isolated to unauthenticated traffic; signed-in users were not affected. The issue was caused by a significant increase in abusive traffic to specific GitHub.com endpoints. This degraded our ability to respond to unauthenticated requests, causing requests to queue beyond timeout thresholds and return gateway timeout errors. We mitigated the incident by identifying the anomalous traffic pattern and applying targeted blocks at the load balancer and application layers. Error rates returned to normal and affected services were fully restored by 08:36 UTC. To reduce the likelihood and impact of similar inc

1. Resolved · Jun 8, 08:36 UTC
   On June 8, 2026, between approximately 06:30 UTC and 08:36 UTC, signed-out users experienced sustained elevated HTTP 504 errors when accessing Pull Requests, Issues, releases, patch diffs, and other related GitHub.com pages. During the incident, approximately 17% of unauthenticated requests to the affected GitHub.com endpoints returned gateway timeout errors, peaking at roughly 34% of requests at around 06:50 UTC. Some GitHub Actions workflows were also affected when they depended on release downloads or related GitHub.com endpoints. The impact lasted approximately two hours and was isolated to unauthenticated traffic; signed-in users were not affected. The issue was caused by a significant increase in abusive traffic to specific GitHub.com endpoints. This degraded our ability to respond to unauthenticated requests, causing requests to queue beyond timeout thresholds and return gateway timeout errors. We mitigated the incident by identifying the anomalous traffic pattern and applying targeted blocks at the load balancer and application layers. Error rates returned to normal and affected services were fully restored by 08:36 UTC. To reduce the likelihood and impact of similar incidents in the future, we are improving automated detection and blocking for these traffic patterns, improving our emergency traffic-blocking deployment path, and evaluating routing changes for endpoints used by both signed-out users and automated workflows.