GitHub Reports September 2025 Service Disruptions
Felix Pinkston Oct 08, 2025 23:02
GitHub experienced three major service incidents in September 2025, affecting Copilot availability and email delivery. Find out how GitHub addressed these issues.
GitHub encountered several service disruptions in September 2025, affecting various features and services, according to GitHub. The incidents primarily involved issues with their Copilot service and email delivery system, leading to performance degradation and delays for users.
Copilot Availability Issues
On September 15, 2025, between 17:55 and 18:20 UTC, GitHub's Copilot service faced a significant disruption. A feature flag deployment intended to adjust a global rate limiter inadvertently restricted 100% of requests, resulting in numerous 403 errors. The issue was promptly resolved by reverting the feature flag, which restored normal service. GitHub identified an undetected edge case in their rate limiting logic as the root cause and has since implemented traffic anomaly monitors and increased rate limit scaling tests to prevent future occurrences.
Email Delivery Delays
GitHub also experienced email delivery delays on September 23 and 24, 2025. The incidents, caused by unusually high traffic volumes, resulted in resource contention on outbound email servers. Consequently, users experienced email notification delays peaking at about 50 minutes. GitHub has since updated server configurations to better handle high traffic volumes and improved monitoring systems for early detection of similar issues.
API Degradation
The third incident occurred on September 29, 2025, affecting the Copilot API. Between 16:26 and 17:33 UTC, users encountered intermittent 404 errors for a small percentage of requests due to a misconfiguration exposed by an internal dependency upgrade. GitHub resolved the problem by rolling back the upgrade and addressing the misconfiguration. They plan to enhance documentation and refine their rollout processes to prevent similar disruptions in the future.
For real-time updates on GitHub's service status and post-incident recaps, users are encouraged to follow their status page.
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