flac123 is a command-line application for playing FLAC audio files.
A possible buffer overflow vulnerability has been reported in the local__vcentry_parse_value() function in vorbiscomment.c.
An attacker could entice a user to play a specially crafted audio file, which could lead to the execution of arbitrary code with the privileges of the user running the application.
There is no known workaround at this time.
All flac123 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-sound/flac123-0.0.11"