When exiting fullscreen mode, an iframe could have confused the browser about the current state of fullscreen, resulting in potential user confusion or spoofing attacks. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.
| Software | From | Fixed in |
|---|---|---|
| mozilla / firefox | - | 101 |
| mozilla / firefox_esr | - | 91.10 |
| mozilla / thunderbird | - | 91.10 |