A use-after-free vulnerability can occur in the Fetch API when the worker or the associated window are freed when still in use, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.
The Developer Tools feature suffers from a XUL injection vulnerability due to improper sanitization of the web page source code. In the worst case, this could allow arbitrary code execution when opening a malicious page with the style editor tool. This vulnerability affects Firefox ESR < 52.3 and Firefox < 55.
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.
A use-after-free vulnerability can occur while re-computing layout for a "marquee" element during window resizing where the updated style object is freed while still in use. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
A use-after-free vulnerability can occur when manipulating the DOM during the resize event of an image element. If these elements have been freed due to a lack of strong references, a potentially exploitable crash may occur when the freed elements are accessed. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
When a page's content security policy (CSP) header contains a "sandbox" directive, other directives are ignored. This results in the incorrect enforcement of CSP. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
A use-after-free and use-after-scope vulnerability when logging errors from headers for XML HTTP Requests (XHR). This could result in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
A use-after-free vulnerability in IndexedDB when one of its objects is destroyed in memory while a method on it is still being executed. This results in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
An out-of-bounds read vulnerability with the Opus encoder when the number of channels in an audio stream changes while the encoder is in use. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
Default fonts on OS X display some Tibetan characters as whitespace. When used in the addressbar as part of an IDN this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.