GitHub's platform endured a turbulent March 2026, with four distinct incidents leading to degraded performance across its services. Notably, these outages affected the availability of GitHub Copilot, the AI-powered coding assistant. The details, published on the GitHub Blog, reveal a complex web of interconnected issues.
The most significant outage occurred on March 3rd, lasting over an hour. A bug during a cache update deployment caused widespread cache expiration and recalculation, impacting github.com, the API, GitHub Actions, Git operations, and critically, GitHub Copilot. At its peak, GitHub.com saw a 40% failure rate, with GitHub Copilot requests experiencing a 21% error rate.
This incident stemmed from the same underlying cause as an earlier February outage, highlighting ongoing challenges with the user settings caching mechanism. GitHub is implementing immediate fixes, including a killswitch for the cache and moving it to a dedicated host to prevent cascading failures.
Copilot Agent Service Disruptions
Further compounding the issues, the Copilot Coding Agent service itself suffered two separate degradations on March 19th and 20th. These incidents, lasting 48 minutes and nearly 1.5 hours respectively, rendered users unable to start or view Copilot sessions.
The core problem was an authentication system failure preventing the service from connecting to its datastore. High error rates, reaching 93% and 99% during these events, underscore the severity of the disruption. Both incidents were mitigated by rotating credentials, though the second occurrence was due to an incomplete fix from the first.
GitHub acknowledges the disruptions and is investing in long-term resilience, alongside urgent improvements. These include enhanced monitoring and architectural overhauls to prevent future widespread GitHub Copilot integration issues.
Additional incidents impacted GitHub Actions due to Redis infrastructure misconfigurations and Microsoft Teams integration due to upstream dependency outages, further illustrating the platform's interconnected vulnerabilities.
