The (1) XvQueryAdaptors and (2) XvQueryEncodings functions in X.org libXv before 1.0.11 allow remote X servers to trigger out-of-bounds memory access operations via vectors involving length specifications in received data.
https://security.gentoo.org/glsa/201704-03
https://lists.x.org/archives/xorg-announce/2016-October/002720.html
https://cgit.freedesktop.org/xorg/lib/libXv/commit/?id=d9da580b46a28ab497de2e94fdc7b9ff953dab17
http://www.securitytracker.com/id/1036945
http://www.securityfocus.com/bid/93368