The Gst.MapInfo function in Vala 0.26.0 and 0.26.1 uses an incorrect buffer length declaration for the Gstreamer bindings, which allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via unspecified vectors, which trigger a heap-based buffer overflow.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.