PHP has been updated to the following versions 5.4.45, 5.5.31, 5.6.17 to patch a security vulnerability in OpenSSL. We have noticed a few customers affected by SSL issues since the PHP release if they are connecting to MySQL via SSL. The fix is to update the cipher or provide a certificate for the connection. Relevant information is available here:
https://php.net/manual/en/mysqli.ssl-set.php.