Today OpenSSL has issued a new security update. The release can be found at: https://mta.openssl.org/pipermail/openssl-announce/2015-March/000026.html
If you are using WordPress OAuth Server and are using SSL with OpenSSL, it is advised that you update to the latest version.
If you are not using SSL or OpenSSL, you have nothing to worry about but you SHOULD be securing your connections when using WordPress OAuth Server.