Heap-based buffer overflow in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2 allows remote attackers to execute arbitrary code via foreign-context HTML5 fragments, as demonstrated by fragments within an SVG element.
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.