Certain input to the CSS Sanitizer confused it, resulting in incorrect components being removed. This could have been used as a sanitizer bypass. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.
| Software | From | Fixed in |
|---|---|---|
| mozilla / firefox_esr | - | 78.6.0 |
| mozilla / thunderbird | - | 78.6.0 |
| mozilla / firefox | - | 84.0 |