The announcement of September 30 sets the entry into force on October 7, 2026. The title of the URL still contains "September-15": the date retained here follows the title and the text of the official publication.
Which scope is affected?
The change concerns GitHub Enterprise Cloud with data residency. HTTPS connections of clients offering only X25519 will no longer be accepted. P-256 and P-384 remain supported; SSH is not affected. GitHub specifies that most current customers do not ask for action.
A proportionate control before the deadline
Examine applications, TLS libraries, proxies, and devices explicitly limited to X25519. The supplier requests to remove this limitation and to check the availability of P-256. The GitHub Official Publication Details the scope and accepted groups.
Prepare a verification of your own channel
As a control method, list the components used between your tool and the service, write down their managers and then test a real journey. Retain the result and a recovery procedure if an automation fails. This method proposal does not mean that your environment is affected. The Incident Response Guide Help to organize this follow-up.