The WooCommerce 2.3.13 release is now available via WordPress.org or automatic update in your administration panel.
A total of 32 commits made it into this (and the 2.3.12) release.
One small but important fix in 2.3.12 was related to SSL detection. WooCommerce for the most part relies on the WordPress function is_ssl() to detect whether or not a page is being served via SSL. WooCommerce had a small function for making this function compatible with some edge-case hosting environments. This however was causing some installs of Google Chrome to incorrectly think a URL was SSL.
Because of this, fix_server_vars has been removed. If you are on an affected host (using load balancers or proxies) you may need to add some handling for this yourself. See http://docs.woothemes.com/document/ssl-and-https/#websites-behind-load-balancers-or-reverse-proxies
2.3.13 made a small fix in the email settings which some 3rd party developers requested.
Other than that, there are just minor fixes and one security/escaping fix in one of the template files which you can read about in the changelog.
(As always, the comments on this post are closed because this is not the right platform for support requests.)