The qtdemux_tag_add_str_full function in gst/isomp4/qtdemux.c in gst-plugins-good in GStreamer before 1.10.3 allows remote attackers to cause a denial of service (out-of-bounds read and crash) via a crafted tag value.
The vmnc decoder in the gstreamer does not initialize the render canvas, which allows remote attackers to obtain sensitive information as demonstrated by thumbnailing a simple 1 frame vmnc movie that does not draw to the allocated render canvas.