tl;dr: The Flying Circus is not affected by the Heartbleed bug
As reported by several media there is a serious bug in the OpenSSL library, widely known as the Heartbleed bug. The bug was introduced in the OpenSSL development tree on January 1st, 2012 and was finally released with OpenSSL version 1.0.1.
The Flying Circus platform makes use of the Gentoo Linux distribution. The OpenSSL version maintained for the Flying Circus is 1.0.0j, so it is not affected by the Heartbleed bug.
To be sure we are not affected by the bug, for example by possible backports from the Gentoo maintainer, we also audited the OpenSSL sources that are in use to not implement the vulnerable heartbeat function.
The Flying Circus is not affected by Heartbleed and there was no time in the past when we had rolled out a vulnerable version.
There is no need to replace your certificates or keys.