It is possible to execute JavaScript in the parsed RSS feed when RSS feed is viewed as a website, e.g. via "View -> Feed article -> Website" or in the standard format of "View -> Feed article -> default format". This vulnerability affects Thunderbird < 52.5.2.

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.

When packets with a mismatched RTP payload type are sent in WebRTC connections, in some circumstances a potentially exploitable crash is triggered. This vulnerability affects Firefox ESR < 52.7 and Firefox < 59.

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.

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.

Memory safety bugs were reported in Firefox 55 and Firefox ESR 52.3. 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 < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

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.