The 2.4 series release notes contain important changes in this release series.

Security Fixes

• HIGH Due to the way that email addresses with Unicode in the 'local part' are handled, it was possible to generate a password reset token for an email address and have it delivered to a separate email address with Unicode homoglyphs that normalized to the original email address.
• LOW Admin users could still access user reports after being suspended.
• Packages have been updated to the latest security versions.

Bug Fixes

• LDAP sync failed on suspended users if restricted groups are not configured.

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.
• The management console settings interface doesn't clearly show if you have previously uploaded certificate files or a private key.
• Custom firewall rules aren't maintained during an upgrade.
• Enqueued background jobs are sometimes not purged when a repository is deleted.
• Trying to add a file to a repository with Subversion 1.9 clients incorrectly detects the file already exists and fails.
• 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.

Thanks!

The GitHub Team