CMake/Help/variable/CMAKE_VERSION.rst

CMAKE_VERSION
-------------

The full version of cmake in major.minor.patch[.tweak[-id]] format.

This specifies the full version of the CMake executable being run.
This variable is defined by versions 2.6.3 and higher.  See variables
CMAKE_MAJOR_VERSION, CMAKE_MINOR_VERSION, CMAKE_PATCH_VERSION, and
CMAKE_TWEAK_VERSION for individual version components.  The [-id]
component appears in non-release versions and may be arbitrary text.