Libnids is a component of a network intrusion detection system.
There is a bug in the part of libnids code responsible for TCP reassembly. The flaw probably allows remote code execution.
A remote attacker could possibly execute arbitrary code.
There is no known workaround at this time.
It is recommended that all Gentoo Linux users who are running net-libs/libnids update their systems as follows:
# emerge sync
# emerge -pv '>=net-libs/libnids-1.18'
# emerge '>=net-libs/libnids-1.18'
# emerge clean