In May 2025, GitHub experienced three significant service disruptions affecting different features. The first incident on May 1 involved a new feature causing CORS errors, impacting around 130,000 users who were unable to upload attachments for 45 minutes; this was resolved by rolling back the feature and adding new monitoring metrics. The second incident on May 28 resulted in delayed job starts for GitHub Actions using Ubuntu-24 hosted runners due to a backend caching misconfiguration, affecting 19.7% of jobs, and was mitigated by updating the backend and scaling up runner pools. The third incident on May 30 was a complete service outage of the Microsoft Teams GitHub integration due to an authentication issue with a downstream provider, lasting nearly eight hours; this was addressed by collaborating with the provider and plans to implement more robust authentication methods. GitHub is taking measures to enhance monitoring, failover resiliency, and authentication processes to prevent future occurrences, with more details available on their status page and engineering blog.