Memory safety bugs were reported in Firefox 50.1 and Firefox ESR 45.6. 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 < 45.7, Firefox ESR < 45.7, and Firefox < 51.

A use-after-free vulnerability in frame selection triggered by a combination of malicious script content and key presses by a user. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

A buffer overflow can occur when the image renderer attempts to paint non-displayable SVG elements. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

The Pocket toolbar button, once activated, listens for events fired from it's own pages but does not verify the origin of incoming events. This allows content from other origins to fire events and inject content and commands into the Pocket context. Note: this issue does not affect users with e10s enabled. This vulnerability affects Firefox ESR < 45.6 and Firefox < 50.1.

An out-of-bounds write vulnerability while decoding improperly formed BinHex format archives. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Video files loaded video captions cross-origin without checking for the presence of CORS headers permitting such cross-origin use, leading to potential information disclosure for video captions. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

A use-after-free can occur when events are fired for a "FontFace" object after the object has been already been destroyed while working with fonts. This results in a potentially exploitable crash. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

Use-after-free while manipulating DOM events and removing audio elements due to errors in the handling of node adoption. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.

An out-of-bounds read during the processing of glyph widths during text layout. This results in a potentially exploitable crash and could allow an attacker to read otherwise inaccessible memory. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Memory safety bugs were reported in Firefox 52, Firefox ESR 45.8, Firefox ESR 52, and Thunderbird 52. 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 < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.