Mozilla Firefox before 53.0, Thunderbird before 52.1 or Firefox ESR 52.x before 52.1 :- Mozilla developers and community members Christian Holler, Jon Coppeard, Milan Sreckovic, Tyson Smith, Ronald Crane, Randell Jesup, Philipp, Tooru Fujisawa, and Kan-Ru Chen reported memory safety bugs present in Firefox and Firefox ESR. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.