PVS-Studio warning V576 for Synergy

DWORD dwMajorVersion;
DWORD dwMinorVersion;

std::string
CArchSystemWindows::getOSName() const
{
  ....
  char buffer[100];
  sprintf(buffer, "Microsoft Windows %d.%d",
          info.dwMajorVersion, info.dwMinorVersion);
  ....
}

This suspicious code was found in Synergy project by PVS-Studio static code analyzer.
Warning message is:
V576 Incorrect format. Consider checking the third actual argument of the 'sprintf' function. The SIGNED integer type argument is expected. carchsystemwindows.cpp 90

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/