A use-after-free vulnerability can occur during XSL transformations when the source document for the transformation is manipulated by script content during the transformation. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.

A use-after-free vulnerability can occur while editing events in form elements on a page, resulting in a potentially exploitable crash. This vulnerability affects Firefox ESR < 52.6 and Thunderbird < 52.6.

An integer overflow vulnerability in the Skia library when allocating memory for edge builders on some systems with at least 8 GB of RAM. This results in the use of uninitialized memory, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.

A use-after-free vulnerability can occur during WebRTC connections when interacting with the DTMF timers. This results in a potentially exploitable crash. This vulnerability affects Firefox ESR < 52.6 and Firefox < 58.

Memory safety bugs were reported in Firefox 57 and Firefox ESR 52.5. 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. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.