GitHub outage on Sep 20, 2026: incident with Pull Requests

Reports during the incident

Every 15 minutes, 21:00 UTC to 00:30 UTC. Grey: normal. Red line: official incident.

21:00 UTC22:13 UTC23:22 UTC00:30 UTC

What people reported

0 reports during the incident

No reports in this window.

GitHub's updates

Quoted from www.githubstatus.com

22:13 UTC
Investigating
We are investigating reports of degraded performance for Pull Requests
22:27 UTC
Monitoring
The degradation affecting Pull Requests has been mitigated. We are monitoring to ensure stability.
22:32 UTC
Monitoring
A git fileserver issue caused a brief delay in creating some merge commits - we've isolated the underlying server and already observed recovery.
23:22 UTC
Resolved
On September 20, 2026, between 21:46 and 22:24 UTC the Pull Requests service was degraded and pull request merge and test-merge commits were created late, with delays reaching approximately four minutes at peak. Merge commits were delayed rather than lost. Because some Actions workflow runs start only after a pull request's merge commit is created, a subset of workflow runs for pull request events were also delayed. This was due to a routine repository maintenance job for an unusually large repository consuming nearly all of the memory on a single Git storage server, which left that server unable to serve the Git operations used to create merge commits. We mitigated the incident by removing the affected server from service at 22:18 UTC, after which the queued merge commits were created within six minutes. We have capped the memory a single repository maintenance job may consume so that one repository cannot exhaust a server, and we have improved monitoring and alerting on storage server health to reduce our time to detection and mitigation of issues like this one in the future.

Other GitHub incidents

Nov 8

1 h 57 minIncrease in timeouts for some unauthenticated users Details

Nov 5

45 minDegraded performance for multiple GitHub services Details

Nov 5

52 minIncident with Actions Details

All GitHub incidents

Other agents

Know the moment it's back.

Coral shows it in your Mac's notch, and tells you which agent needs you. Free.

Get Coral for Mac

GitHub's updates

22:13 UTC

Investigating

We are investigating reports of degraded performance for Pull Requests

22:27 UTC

Monitoring

The degradation affecting Pull Requests has been mitigated. We are monitoring to ensure stability.

22:32 UTC

Monitoring

A git fileserver issue caused a brief delay in creating some merge commits - we've isolated the underlying server and already observed recovery.

23:22 UTC

Resolved

On September 20, 2026, between 21:46 and 22:24 UTC the Pull Requests service was degraded and pull request merge and test-merge commits were created late, with delays reaching approximately four minutes at peak. Merge commits were delayed rather than lost. Because some Actions workflow runs start only after a pull request's merge commit is created, a subset of workflow runs for pull request events were also delayed. This was due to a routine repository maintenance job for an unusually large repository consuming nearly all of the memory on a single Git storage server, which left that server unable to serve the Git operations used to create merge commits. We mitigated the incident by removing the affected server from service at 22:18 UTC, after which the queued merge commits were created within six minutes. We have capped the memory a single repository maintenance job may consume so that one repository cannot exhaust a server, and we have improved monitoring and alerting on storage server health to reduce our time to detection and mitigation of issues like this one in the future.