WebExtensions could use popups and panels in the extension UI to load an "about:" privileged URL, violating security checks that disallow this behavior. This vulnerability affects Firefox < 56.

The AES-GCM implementation in WebCrypto API accepts 0-length IV when it should require a length of 1 according to the NIST Special Publication 800-38D specification. This might allow for the authentication key to be determined in some instances. This

The "instanceof" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator, possibly tricking the browser or extension into mishandl

Inside the JavaScript parser, a cast of an integer to a narrower type can result in data read from outside the buffer being parsed. This usually results in a non-exploitable crash, but can leak a limited amount of information from memory if it matche

A vulnerability where WebExtensions can download and attempt to open a file of some non-executable file types. This can be triggered without specific user interaction for the file download and open actions. This could be used to trigger known vulnera

During TLS 1.2 exchanges, handshake hashes are generated which point to a message buffer. This saved data is used for later messages but in some cases, the handshake transcript can exceed the space available in the current buffer, causing the allocat

A buffer overflow occurs when drawing and validating elements with the ANGLE graphics library, used for WebGL content. This is due to an incorrect value being passed within the library during checks and results in a potentially exploitable crash. Thi

The content security policy (CSP) "sandbox" directive did not create a unique origin for the document, causing it to behave as if the "allow-same-origin" keyword were always specified. This could allow a Cross-Site Scripting (XSS) attack to be launch

A use-after-free vulnerability can occur in design mode when image objects are resized if objects referenced during the resizing have been freed from memory. This results in a potentially exploitable crash. This vulnerability affects Firefox < 56, Fi

A use-after-free vulnerability can occur when manipulating arrays of Accessible Rich Internet Applications (ARIA) elements within containers through the DOM. This results in a potentially exploitable crash. This vulnerability affects Firefox < 56, Fi

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

Several fonts on OS X display some Tibetan and Arabic 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 sy

File downloads encoded with "blob:" and "data:" URL elements bypassed normal file download checks though the Phishing and Malware Protection feature and its block lists of suspicious sites and files. This would allow malicious sites to lure users int

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 affect

Memory safety bugs were reported in Firefox 55. 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.

On pages containing an iframe, the "data:" protocol can be used to create a modal dialog through Javascript that will have an arbitrary domains as the dialog's location, spoofing of the origin of the modal dialog from the user view. Note: This attack

If web content on a page is dragged onto portions of the browser UI, such as the tab bar, links can be opened that otherwise would not be allowed to open. This can allow malicious web content to open a locally stored file through "file:" URLs. This v

A spoofing vulnerability can occur when a page switches to fullscreen mode without user notification, allowing a fake address bar to be displayed. This allows an attacker to spoof which page is actually loaded and in use. Note: This attack only affec