libmcpp is a portable C/C++ preprocessor.
A buffer overflow and an out-of-bounds read vulnerability have been discovered in libmcpp, which could be exploited for denial of service.
An attacker that can provide crafted input to libmcpp could achieve denial of service.
There is no known workaround at this time.
All libmcpp users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-cpp/libmcpp-2.7.2_p5"