Incident History

This incident has been resolved. Thank you for your patience and understanding as we addressed this issue. A detailed root cause analysis will be shared as soon as it is available.

This incident has been resolved. Thank you for your patience and understanding as we addressed this issue. A detailed root cause analysis will be shared as soon as it is available.

This incident has been resolved. Thank you for your patience and understanding as we addressed this issue. A detailed root cause analysis will be shared as soon as it is available.

On November 28th, 2025, between approximately 05:51 and 08:04 UTC, Copilot experienced an outage affecting the Claude Sonnet 4.5 model. Users attempting to use this model received an HTTP 400 error, resulting in 4.6% of total chat requests during this timeframe failing. Other models were not impacted.The issue was caused by a misconfiguration deployed to an internal service which made Claude Sonnet 4.5 unavailable. The problem was identified and mitigated by reverting the change. GitHub is working to improve cross-service deploy safeguards and monitoring to prevent similar incidents in the future.

On November 24, 2025, between 12:15 and 15:04 UTC, Codespaces users encountered connection issues when attempting to create a codespace after choosing the recently released VS Code Codespaces extension, version 1.18.1. Users were able to downgrade to the 1.18.0 version of the extension during this period to work around this issue. At peak, the error rate was 19% of connection requests. This was caused by mismatching version dependencies for the released VS Code Codespaces extension.The connection issues were mitigated by releasing the VS Code Codespaces extension version 1.18.2 that addressed the issue. Users utilizing version 1.18.1 of the VS Code Codespaces extension are advised to upgrade to version >=1.18.2.We are improving our validation and release process for this extension to ensure functional issues like this are caught before release to customers and to reduce detection and mitigation times for extension issues like this in the future.

Between November 20, 2025 17:16 UTC to November, 2025 19:08 UTC some users experienced delayed or failed Git Operations for raw file downloads. On average, the error rate was less than 0.2%. This was due to a sustained increase in unauthenticated repository traffic.We mitigated the incident by applying regional rate limiting and are taking steps to improve our monitoring and time to mitigation for similar issues in the future.

On November 19, between 17:36 UTC and 18:04 UTC, GitHub Actions service experienced degraded performance that caused excessive latency in queueing and updating workflow runs and job statuses. Operations related to artifacts, cache, job steps and logs also had significantly increased latency. At peak, 67% of workflow jobs queued during that timeframe were impacted, and the median latency for impacted operations increased by up to 35x.This was caused by a significant change in load pattern on Actions Cache-related operations, leading to a saturated shared resource on the backend. The impact was mitigated by mitigating the new load pattern.To reduce the likelihood of a recurrence, we are improving rate-limiting measures in this area to ensure a more consistent experience for all customers. We are also evaluating changes to reduce the scope of impact.

Between November 19th, 16:13UTC and November 21st, 12:22UTC, the GitHub Enterprise Importer (GEI) service was in a degraded state, during which time, customers of the service experienced a delay when reclaiming mannequins post-migration.We have taken steps to prevent similar incidents from occurring in the future.

From Nov 18, 2025 20:30 UTC to Nov 18, 2025 21:34 UTC we experienced failures on all Git operations, including both SSH and HTTP Git client interactions, as well as raw file access. These failures also impacted products that rely on Git operations.The root cause was an expired TLS certificate used for internal service-to-service communication. We mitigated the incident by replacing the expired certificate and restarting impacted services. Once those services were restarted we saw a full recovery.We have updated our alerting to cover the expired certificate and are performing an audit of other certificates in this area to ensure they also have the proper alerting and automation before expiration. In parallel, we are accelerating efforts to eliminate our remaining manually managed certificates, ensuring all service-to-service communication is fully automated and aligned with modern security practices.

Between November 17, 2025 21:24 UTC and November 18, 2025 00:04 UTC the gists service was degraded and users were unable to create gists via the web UI. 100% of gist creation requests failed with a 404 response. This was due to a change in the web middleware that inadvertently triggered a routing error. We resolved the incident by rolling back the change. We are working on more effective monitoring to reduce the time it takes to detect similar issues and evaluating our testing approach for middleware functionality.