Memory safety bugs were reported 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. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability with the frameloader during tree reconstruction while regenerating CSS layout when attempting to use a node in the tree that no longer exists. This results in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability when using an incorrect URL during the reloading of a docshell. This results in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability during video control operations when a "<track>" element holds a reference to an older window if that window has been replaced in the DOM. This results in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability with content viewer listeners that results in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability during specific user interactions with the input method editor (IME) in some languages due to how events are handled. This results in a potentially exploitable crash but would require specific user interaction to trigger. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
An out-of-bounds read occurs when applying style rules to pseudo-elements, such as ::first-line, using cached style data. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
An out-of-bounds read in WebGL with a maliciously crafted "ImageInfo" object during WebGL operations. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability when holding a selection during scroll events. 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 use-after-free vulnerability during changes in style when manipulating DOM elements. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.