xine-lib is the core library of xine, a multimedia player.
There is a stack based overflow in the libmms library included with xine-lib which can be triggered by malicious use of the send_command, string_utf16, get_data and get_media_packet functions.
A remote attacker could design a malicious media file that would trigger the overflow, potentially resulting in the execution of arbitrary code.
There is no known workaround at this time.
All xine-lib users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/xine-lib-1.1.2-r2"