An integer overflow can occur during graphics operations done by the Supplemental Streaming SIMD Extensions 3 (SSSE3) scaler, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

An integer overflow can occur in the SwizzleData code while calculating buffer sizes. The overflowed value is used for subsequent graphics computations when their inputs are not sanitized which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60, Firefox ESR < 60.1, and Firefox < 61.

A use-after-free vulnerability can occur when deleting an input element during a mutation event handler triggered by focusing that element. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

A buffer overflow can occur when rendering canvas content while adjusting the height and width of the canvas element dynamically, causing data to be written outside of the currently computed boundaries. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

Plaintext of decrypted emails can leak through by user submitting an embedded form. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

Using remote content in encrypted messages can lead to the disclosure of plaintext. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

Mozilla developers backported selected changes in the Skia library. These changes correct memory corruption issues including invalid buffer reads and writes during graphic operations. This vulnerability affects Thunderbird ESR < 52.8, Thunderbird < 52.8, and Firefox ESR < 52.8.

A buffer overflow was found during UTF8 to Unicode string conversion within JavaScript with extremely large amounts of data. This vulnerability requires the use of a malicious or vulnerable legacy extension in order to occur. This vulnerability affects Thunderbird ESR < 52.8, Thunderbird < 52.8, and Firefox ESR < 52.8.

In the Windows 10 April 2018 Update, Windows Defender SmartScreen honors the "SEE_MASK_FLAG_NO_UI" flag associated with downloaded files and will not show any UI. Files that are unknown and potentially dangerous will be allowed to run because SmartScreen will not prompt the user for a decision, and if the user is offline all files will be allowed to be opened because Windows won't prompt the user to ask what to do. Firefox incorrectly sets this flag when downloading files, leading to less secure behavior from SmartScreen. Note: this issue only affects Windows 10 users running the April 2018 update or later. It does not affect other Windows users or other operating systems. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

It is possible to spoof the filename of an attachment and display an arbitrary attachment name. This could lead to a user opening a remote attachment which is a different file type than expected. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

Sites can bypass security checks on permissions to install lightweight themes by manipulating the "baseURI" property of the theme element. This could allow a malicious site to install a theme without user interaction which could contain offensive or embarrassing images. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

Plaintext of decrypted emails can leak through the src attribute of remote images, or links. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

Crafted message headers can cause a Thunderbird process to hang on receiving the message. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

An integer overflow can occur in the Skia library due to 32-bit integer use in an array without integer overflow checks, resulting in possible out-of-bounds writes. This could lead to a potentially exploitable crash triggerable by web content. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

A use-after-free vulnerability can occur while adjusting layout during SVG animations with text paths. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

A use-after-free vulnerability can occur while enumerating attributes during SVG animations with clip paths. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

Memory safety bugs were reported in Firefox 59, Firefox ESR 52.7, and Thunderbird 52.7. 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 < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

An out of bounds memory write while processing Vorbis audio data was reported through the Pwn2Own contest. This vulnerability affects Firefox < 59.0.1, Firefox ESR < 52.7.2, and Thunderbird < 52.7.

Memory safety bugs were reported in Firefox ESR 52.6. 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 ESR < 52.7 and Thunderbird < 52.7.

An integer overflow can occur during conversion of text to some Unicode character sets due to an unchecked length parameter. This vulnerability affects Firefox ESR < 52.7 and Thunderbird < 52.7.