libvpx is the VP8 codec SDK used to encode and decode video streams, typically within a WebM format media file.
libvpx is vulnerable to an integer overflow vulnerability when processing crafted VP8 video streams.
A remote attacker could entice a user to open a specially crafted media file, 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 libvpx users should upgrade to the latest stable version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libvpx-0.9.5"
Packages which depend on this library may need to be recompiled. Tools such as revdep-rebuild may assist in identifying some of these packages.