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.
[
{
"product": "Firefox",
"vendor": "Mozilla",
"versions": [
{
"lessThan": "59",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
}
]