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.