libvorbis is the reference implementation of the Xiph.org Ogg Vorbis audio file format. It is used by many applications for playback of Ogg Vorbis files.
Lucas Adamski reported that libvorbis does not correctly process file headers, related to static mode headers and encoding books.
A remote attacker could entice a user to play a specially crafted OGG Vorbis file using an application that uses libvorbis, possibly resulting in the execution of arbitrary code with the privileges of the user running the application, or a Denial of Service.
There is no known workaround at this time.
All libvorbis users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libvorbis-1.2.3"