The 2.9 series release notes contain important changes in this release series.

Security Fixes

• MEDIUM: GitHub Services webhooks could be configured to use non-HTTP protocols.
• Packages have been updated to the latest security versions.

Bug Fixes

• Repository read priority was incorrect after promoting a high availability replica and then re-introducing the original primary node as a replica. This can have a significant performance impact.
• Repository read performance could be severely impacted on very large instances under moderate load.
• The admin:pre_receive_hook scope wasn't displayed when authorizing an Oauth application requesting this particular scope.
• Cloning or pushing repositories with Git LFS assets could fail with a '500 Internal Server Error'.

Changes

• SSH keys added to a user via LDAP sync are automatically verified.

Known Issues

• We incorrectly redirect to the dashboard if you accessed GitHub Enterprise using an alias while in private mode. This might happen if you set a fully qualified domain name but the subdomain resolves correctly.
• Images uploaded to issues save with an absolute URL, so they can be broken if the hostname changes.
• On a freshly set up GitHub Enterprise without any users, an attacker could create the first admin user.
• Custom firewall rules aren't maintained during an upgrade.
• svn checkout may timeout while the repository data cache is being built. In most cases, subsequent svn checkout attempts will succeed.
• Git LFS tracked files uploaded through the web interface are incorrectly added directly to the repository.
• GitHub Enterprise clustering can not be configured without https.
• Deleting a search index doesn't delete all associated metadata, which are then incorrectly reused if a new search index is created. This causes search index repair jobs to be reported as finished in the site admin when they were not.
• After changing the visibility of a repository, wiki search results have a conflicting number of displayed search results. Administrators can reindex the wiki through the site admin dashboard. (updated 2017-11-09)
• The create team API endpoint returns a 500 error if LDAP Sync is enabled and the team already exists. (updated 2018-01-09)

Thanks!

The GitHub Team