External resources that should be blocked when loaded by SVG images can bypass security restrictions through the use of "data:" URLs. This could allow for cross-domain data leakage. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.

Event handlers on "marquee" elements were executed despite a strict Content Security Policy (CSP) that disallowed inline JavaScript. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.

A use-after-free vulnerability can occur in WebSockets when the object holding the connection is freed before the disconnection operation is finished. This results in an exploitable crash. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

Hashed codes of JavaScript objects are shared between pages. This allows for pointer leaks because an object's address can be discovered through hash codes, and also allows for data leakage of an object's content using these hash codes. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

A crash triggerable by web content in which an "ErrorResult" references unassigned memory due to a logic error. The resulting crash may be exploitable. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

A use-after-free vulnerability occurs during transaction processing in the editor during design mode interactions. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

URLs containing certain unicode glyphs for alternative hyphens and quotes do not properly trigger punycode display, allowing for domain name spoofing attacks in the location bar. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Memory corruption resulting in a potentially exploitable crash during garbage collection of JavaScript due errors in how incremental sweeping is managed for memory cleanup. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

A use-after-free vulnerability in SMIL animation functions occurs when pointers to animation elements in an array are dropped from the animation controller while still in use. 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 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.