Note that this is a server configuration issue, and not something that is related to the certificate. Make sure that your server has installed all available updates (especially for OpenSSL) and that your server configuration is okay. The Mozilla SSL Configuration Generator is a good starting point.
To add on to @pfg’s reply, if you are using OpenSSL you will need to make sure that you update to OpenSSL version 1.0.2h or newer if you use the 1.0.2x release, or version 1.0.1t or newer if you use the 1.0.1x release.
Yup ssllabs now tests for CVE-2016-2107 and problem is directly related to OpenSSL needing 1.0.2h or if you’re using LibreSSL at least 2.3.4+. Test your sites via https://filippo.io/CVE-2016-2107/ as well to see if your web server and underlying OpenSSL is vulnerable