Between 13:25 UTC and 18:35 UTC on December 11th, GitHub experienced elevated traffic to portions of GitHub.com that exceeded previously provisioned capacity for specific request types. As a result, users encountered intermittent 500 errors. Impact was most pronounced on Login, Logout, and Signup pages, peaking at 7.6% of login requests. Additionally, fewer than 1% of requests originating from GitHub Actions jobs were affected.
Our immediate response focused on identifying and mitigating the source of the traffic increase. We increased available capacity for web request handling to relieve pressure on constrained pools. To reduce recurrence risk, we also re-routed critical authentication endpoints to a different traffic pool, ensuring sufficient isolation and headroom for login related traffic.
In future, we’re working to more proactively identify these large changes in traffic volume and improve our time to mitigation.
Posted Dec 11, 2025 - 17:53 UTC
Update
Git Operations is operating normally.
Posted Dec 11, 2025 - 17:20 UTC
Update
We believe that we have narrowed down our affected users to primarily those that are signing up or signing in as well as logged out usage. We are currently continuing to investigate the root cause and are working multiple mitigation angles.
Posted Dec 11, 2025 - 17:19 UTC
Update
We are experiencing intermittent web request failures across multiple services, including login and authentication. Our teams are actively investigating the cause and working on mitigation.
Posted Dec 11, 2025 - 16:41 UTC
Update
Codespaces, Copilot, Git Operations, Packages, Pages, Pull Requests and Webhooks are experiencing degraded performance. We are continuing to investigate.
Posted Dec 11, 2025 - 16:09 UTC
Update
API Requests and Actions are experiencing degraded performance. We are continuing to investigate.
Posted Dec 11, 2025 - 16:01 UTC
Investigating
We are investigating reports of degraded performance for Issues
Posted Dec 11, 2025 - 15:47 UTC
This incident affected: Git Operations, Webhooks, API Requests, Issues, Pull Requests, Actions, Packages, Pages, Codespaces, and Copilot.