Mozilla Firefox before 54.0, Firefox ESR before 52.2 or Thunderbird before 52.2 :- Mozilla developers and community members Tyson Smith, Mats Palmgren, Philipp, Masayuki Nakano, Christian Holler, Andrew McCreight, Gary Kwong, Andre Bargull, Carsten Book, Jesse Schwartzentruber, Julian Hector, Marcia Knous, Ronald Crane, and Nils Ohlmeier reported memory safety bugs present in Firefox 53 and Firefox ESR 52.1. 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.