The 2.5 series release notes contain important changes in this release series.

Security Fixes

• CRITICAL Final policies that were pending for the ImageMagick vulnerability (first applied in GitHub Enterprise 2.5.6) have now been applied, to address
  CVE-2016-3714. Note that GitHub Enterprise only uses ImageMagick for PSD files to which the vulnerability did not apply. (updated 2016-07-13)
• HIGH Release assets from a public repository could be accessed by unauthenticated users in private mode. (updated 2016-05-27)
• Packages have been updated to the latest security versions.

Bug Fixes

• CAS logout failed when the CAS server URL includes a path.

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.
• Enqueued background jobs are sometimes not purged when a repository is deleted.
• On instances upgraded from 2.3 and earlier, restoring an archived protected branch will not restore all the settings correctly. This does not affect new instances.
• svn checkout may timeout while the repository data cache is being built. In most cases, subsequent svn checkout attempts will succeed. (updated 2016-05-24)
• Migration data exported from GitHub Enterprise with ghe-migrator does not include issue file attachments, which may cause imports to another server to fail. (updated 2016-06-09)
• Console text is difficult to read on OpenStack KVM. (updated 2016-08-03)
• The initial import of the VMware OVA image may fail when deployed via vCenter Server 6.0 or 6.5. The import will succeed when performed directly on an ESXi host. (updated 2017-02-23)
• Git LFS objects may take up to an hour to replicate in a High Availability configuration. (updated 2017-02-23)

Thanks!

The GitHub Team