Mozilla developers and community members reported several memory safety bugs in the browser engine used in Firefox and other Mozilla-based products. Some of these bugs showed evidence of memory corruption under certain circumstances, and we presume that with enough effort at least some of these could be exploited to run arbitrary code.
Carsten Book, Christian Holler, Gary Kwong, Jesse Ruderman, Andrew McCreight, Phil Ringnalda and Philipp reported memory safety problems and crashes that are fixed in Firefox ESR 45.3 and Firefox 48.
Christian Holler, Tyson Smith, Boris Zbarsky, Byron Campen, and Julian Seward reported memory safety problems and crashes that are fixed in Firefox 48.