A legacy extension's non-contentaccessible, defined resources can be loaded by an arbitrary web page through script. This script does this by using a maliciously crafted path string to reference the resources. Note: this vulnerability does not affect WebExtensions. This vulnerability affects Firefox < 59.

A shared worker created from a "data:" URL in one tab can be shared by another tab with a different origin, bypassing the same-origin policy. This vulnerability affects Firefox < 59.

WebExtensions can bypass normal restrictions in some circumstances and use "browser.tabs.executeScript" to inject scripts into contexts where this should not be allowed, such as pages from other WebExtensions or unprivileged "about:" pages. This vulnerability affects Firefox < 59.

WebExtensions may use "view-source:" URLs to view local "file:" URL content, as well as content stored in "about:cache", bypassing restrictions that only allow WebExtensions to view specific content. This vulnerability affects Firefox < 59.

If the "app.support.baseURL" preference is changed by a malicious local program to contain HTML and script content, this content is not sanitized. It will be executed if a user loads "chrome://browser/content/preferences/in-content/preferences.xul" directly in a tab and executes a search. This stored preference is also executed whenever an EME video player plugin displays a CDM-disabled message as a notification message. This vulnerability affects Firefox < 59.

The Find API for WebExtensions can search some privileged pages, such as "about:debugging", if these pages are open in a tab. This could allow a malicious WebExtension to search for otherwise protected data if a user has it open. This vulnerability affects Firefox < 59.

Under certain circumstances the "fetch()" API can return transient local copies of resources that were sent with a "no-store" or "no-cache" cache header instead of downloading a copy from the network as it should. This can result in previously stored, locally cached data of a website being accessible to users if they share a common profile while browsing. This vulnerability affects Firefox ESR < 52.7 and Firefox < 59.

When packets with a mismatched RTP payload type are sent in WebRTC connections, in some circumstances a potentially exploitable crash is triggered. This vulnerability affects Firefox ESR < 52.7 and Firefox < 59.

A lack of parameter validation on IPC messages results in a potential out-of-bounds write through malformed IPC messages. This can potentially allow for sandbox escape through memory corruption in the parent process. This vulnerability affects Thunderbird < 52.7, Firefox ESR < 52.7, and Firefox < 59.

A use-after-free vulnerability can occur when manipulating elements, events, and selection ranges during editor operations. This results in a potentially exploitable crash. This vulnerability affects Firefox < 59.

A buffer overflow can occur when manipulating the SVG "animatedPathSegList" through script. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.7, Firefox ESR < 52.7, and Firefox < 59.

Memory safety bugs were reported in Firefox 58. 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 < 59.

Memory safety bugs were reported in Firefox 58 and Firefox ESR 52.6. 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 < 52.7, Firefox ESR < 52.7, and Firefox < 59.

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.

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 affects OS X operating systems. Other operating systems are unaffected. 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 < 58.

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 file system. This loading is blocked by the sandbox but could expose local data if combined with another attack that escapes sandbox protections. This vulnerability affects Firefox < 58.

If right-to-left text is used in the addressbar with left-to-right alignment, it is possible in some circumstances to scroll this text to spoof the displayed URL. This issue could result in the wrong URL being displayed as a location, which can mislead users to believe they are on a different site than the one loaded. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.

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, bypassing same-origin user expectations with this permission. This vulnerability affects Firefox < 58.

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 user confusion about the originating site of the authentication request and may cause users to mistakenly send private credential information to a third party site. This vulnerability affects Firefox < 58.