Actions failures to download (401 Unauthorized)

Final update

On March 12, 2026 between 02:30 and 06:02 UTC some GitHub Apps were unable to mint server to server tokens, resulting in 401 Unauthorized errors. During the outage window, ~1.3% of requests resulted in 401 errors incorrectly. This manifested in GitHub Actions jobs failing to download tarballs, as well as failing to mint fine-grained tokens. During this period, approximately 5% of Actions jobs were impacted The root cause was a failure with the authentication service’s token cache layer, a newly created secondary cache layer backed by Redis – caused by Kubernetes control plane instability, leading to an inability to read certain tokens which resulted in 401 errors. The mitigation was to fallback reads to the primary cache layer backed by mysql. As permanent mitigations, we have made changes to how we deploy redis to not rely on the Kubernetes control plane and maintain service availability during similar failure modes. We also improved alerting to reduce overall impact time from similar failures.

1. Resolved · Mar 12, 06:02 UTC
   On March 12, 2026 between 02:30 and 06:02 UTC some GitHub Apps were unable to mint server to server tokens, resulting in 401 Unauthorized errors. During the outage window, ~1.3% of requests resulted in 401 errors incorrectly. This manifested in GitHub Actions jobs failing to download tarballs, as well as failing to mint fine-grained tokens. During this period, approximately 5% of Actions jobs were impacted The root cause was a failure with the authentication service’s token cache layer, a newly created secondary cache layer backed by Redis – caused by Kubernetes control plane instability, leading to an inability to read certain tokens which resulted in 401 errors. The mitigation was to fallback reads to the primary cache layer backed by mysql. As permanent mitigations, we have made changes to how we deploy redis to not rely on the Kubernetes control plane and maintain service availability during similar failure modes. We also improved alerting to reduce overall impact time from similar failures.