The VideoFramePool::PoolImpl::CreateFrame function in media/base/video_frame_pool.cc in Google Chrome before 47.0.2526.73 does not initialize memory for a video-frame data structure, which might allow remote attackers to cause a denial of service (out-of-bounds memory access) or possibly have unspecified other impact by leveraging improper interaction with the vp3_h_loop_filter_c function in libavcodec/vp3dsp.c in FFmpeg.
https://code.google.com/p/chromium/issues/detail?id=514759
http://googlechromereleases.blogspot.com/2015/12/stable-channel-update.html