GitHub outage on 2026-08-12: Incident with Pull Requests and Issues

Between 16:03 and 16:29 UTC on August 12, some users encountered errors when viewing pull requests, issues, and search results. During this period, about 1.9% of Pull Request requests and 0.9% of Issues requests failed. During a database migration, two indexes were removed while application settings still referenced them, causing affected requests to fail. We detected the issue after the migration reached one database shard and before it progressed to the remaining shards. We restored service by disabling both settings. We are improving safeguards around database migrations and application configuration to prevent similar mismatches from causing errors.