cmake install issue in RHEL 7.2

gmake: `cmake' is up to date.

/root/cmake-3.9.0/Bootstrap.cmk/cmake: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /root/cmake-3.9.0/Bootstrap.cmk/cmake)

Error when bootstrapping CMake:
Problem while running initial CMake