Earlier today we permanently removed support for the following weak cryptographic standards on github.com and api.github.com:

• TLSv1/TLSv1.1: This applies to all HTTPS connections, including web, API, and Git connections to https://github.com and https://api.github.com.
• diffie-hellman-group1-sha1: This applies to all SSH connections to github.com
• diffie-hellman-group14-sha1: This applies to all SSH connections to github.com

This change was originally announced last year, with the final timeline for the removal posted three weeks ago. If you run into any issues or have any questions, please don’t hesitate to let us know.