The location bar in Firefox for Android can be spoofed by forcing a user into fullscreen mode, blocking its exiting, and creating of a fake location bar without any user notification. Note: This issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 50.

Add-on updates failed to verify that the add-on ID inside the signed package matched the ID of the add-on being updated. An attacker who could perform a man-in-the-middle attack on the user's connection to the update server and defeat the certificate pinning protection could provide a malicious signed add-on instead of a valid update. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

An integer overflow during the parsing of XML using the Expat library. This vulnerability affects Firefox < 50.

Private browsing mode leaves metadata information, such as URLs, for sites visited in "browser.db" and "browser.db-wal" files within the Firefox profile after the mode is exited. Note: This issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 50.

A previously installed malicious Android application which defines a specific signature-level permissions used by Firefox can access API keys meant for Firefox only. Note: This issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 50.

A previously installed malicious Android application with same signature-level permissions as Firefox can intercept AuthTokens meant for Firefox only. Note: This issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 50.

A mechanism where disruption of the loading of a new web page can cause the previous page's favicon and SSL indicator to not be reset when the new page is loaded. Note: this issue only affects Firefox for Android. Desktop Firefox is unaffected. This vulnerability affects Firefox < 50.

An error in argument length checking in JavaScript, leading to potential integer overflows or other bounds checking issues. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

A heap-buffer-overflow in Cairo when processing SVG content caused by compiler optimization, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

This vulnerability allows an attacker to use the Mozilla Maintenance Service to escalate privilege by having the Maintenance Service invoke the Mozilla Updater to run malicious local files. This vulnerability requires local system access and is a variant of MFSA2013-44. Note: this issue only affects Windows operating systems. This vulnerability affects Firefox < 50.

The Mozilla Updater can be made to choose an arbitrary target working directory for output files resulting from the update process. This vulnerability requires local system access. Note: this issue only affects Windows operating systems. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

When the Mozilla Updater is run, if the Updater's log file in the working directory points to a hardlink, data can be appended to an arbitrary local file. This vulnerability requires local system access. Note: this issue only affects Windows operating systems. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

During URL parsing, a maliciously crafted URL can cause a potentially exploitable crash. This vulnerability affects Firefox < 50.

A same-origin policy bypass with local shortcut files to load arbitrary local content from disk. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

Memory safety bugs were reported in Firefox 49 and Firefox ESR 45.4. 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 < 45.5, Firefox ESR < 45.5, and Firefox < 50.

Memory safety bugs were reported in Firefox 49. 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 < 50.

Web content could access information in the HTTP cache if e10s is disabled. This can reveal some visited URLs and the contents of those pages. This issue affects Firefox 48 and 49. This vulnerability affects Firefox < 49.0.2.

A potentially exploitable use-after-free crash during actor destruction with service workers. This issue does not affect releases earlier than Firefox 49. This vulnerability affects Firefox < 49.0.2.

Stack-based buffer overflow in the evutil_parse_sockaddr_port function in evutil.c in libevent before 2.1.6-beta allows attackers to cause a denial of service (segmentation fault) via vectors involving a long string in brackets in the ip_as_string argument.

Mozilla Firefox before 49.0, Firefox ESR 45.x before 45.4, and Thunderbird < 45.4 rely on unintended expiration dates for Preloaded Public Key Pinning, which allows man-in-the-middle attackers to spoof add-on updates by leveraging possession of an X.509 server certificate for addons.mozilla.org signed by an arbitrary built-in Certification Authority.