curl_exec() has been disabled for security reasons

I have upgraded a blog to 2.7. I got this error: Warning: curl_exec() has been disabled for security reasons in /var/www. I installed the list http transports plugin. I indicated that Available transports: Curl Fopen Fsockopen is the only available transport:
Available transports: Curl Fopen Fsockopen. How do I resolve this problem? Do I need to reverse and wait for 2.8?