It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26953.json"
[
{
"events": [
{
"introduced": "0"
},
{
"fixed": "83.0"
}
]
},
{
"events": [
{
"introduced": "0"
},
{
"fixed": "78.5"
}
]
},
{
"events": [
{
"introduced": "0"
},
{
"fixed": "78.5"
}
]
}
]