A potential integer overflow in the "DoCrypt" function of WebCrypto was identified. If a means was found of exploiting it, it could result in an out-of-bounds write. This vulnerability affects Firefox < 58.

WebExtensions can bypass user prompts to first save and then open an arbitrarily downloaded file. This can result in an executable file running with local user privileges without explicit user consent. This vulnerability affects Firefox < 58.

The "browser.identity.launchWebAuthFlow" function of WebExtensions is only allowed to load content over "https:" but this requirement was not properly enforced. This can potentially allow privileged pages to be loaded by the extension. This vulnerabi

Development Tools panels of an extension are required to load URLs for the panels as relative URLs from the extension manifest file but this requirement was not enforced in all instances. This could allow the development tools panel for the extension

If an existing cookie is changed to be "HttpOnly" while a document is open, the original value remains accessible through script until that document is closed. Network requests correctly use the changed HttpOnly cookie. This vulnerability affects Fir

If an HTTP authentication prompt is triggered by a background network request from a page or extension, it is displayed over the currently loaded foreground page. Although the prompt contains the real domain making the request, this can result in use

If cursor visibility is toggled by script using from 'none' to an image and back through script, the cursor will be rendered temporarily invisible within Firefox. Note: This vulnerability only affects OS X. Other operating systems are not affected. T

When the text of a specially formatted URL is dragged to the addressbar from page content, the displayed URL can be spoofed to show a different site than the one loaded. This allows for phishing attacks where a malicious page can spoof the identify o

An audio capture session can started under an incorrect origin from the site making the capture request. Users are still prompted to allow the request but the prompt can display the wrong origin, leading to user confusion about which site is making t

A Blob URL can violate origin attribute segregation, allowing it to be accessed from a private browsing tab and for data to be passed between the private browsing tab and a normal tab. This could allow for the leaking of private information specific

The printing process can bypass local access protections to read files available through symlinks, bypassing local file restrictions. The printing process requires files in a specific format so arbitrary data cannot be read but it is possible that so

Style editor traffic in the Developer Tools can be routed through a service worker hosted on a third party website if a user selects error links when these tools are open. This can allow style editor information used within Developer Tools to leak cr

A heap buffer overflow vulnerability may occur in WebAssembly during Memory/Table resizing, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 58.

A heap buffer overflow vulnerability may occur in WebAssembly when "shrinkElements" is called followed by garbage collection on memory that is now uninitialized. This results in a potentially exploitable crash. This vulnerability affects Firefox < 58

A use-after-free vulnerability can occur when the thread for a Web Worker is freed from memory prematurely instead of from memory in the main thread while cancelling fetch operations. This vulnerability affects Firefox < 58.

Memory safety bugs were reported in Firefox 57. 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 < 58.

The reader view will display cross-origin content when CORS headers are set to prohibit the loading of cross-origin content by a site. This could allow access to content that should be restricted in reader view. This vulnerability affects Firefox < 5

The screenshot images displayed in the Activity Stream page displayed when a new tab is opened is created from the meta tags of websites. An issue was discovered where the page could attempt to create these images through "file:" URLs from the local

WebExtensions with the "ActiveTab" permission are able to access frames hosted within the active tab even if the frames are cross-origin. Malicious extensions can inject frames from arbitrary origins into the loaded page and then interact with them,

Low descenders on some Tibetan characters in several fonts on OS X are clipped when rendered in the addressbar. When used as part of an Internationalized Domain Name (IDN) this can be used for domain name spoofing attacks. Note: This attack only affe

A use-after-free vulnerability can occur when manipulating floating "first-letter" style elements, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 58.

A use-after-free vulnerability can occur when arguments passed to the "IsPotentiallyScrollable" function are freed while still in use by scripts. This results in a potentially exploitable crash. This vulnerability affects Firefox < 58.