| Package | Affected versions | Patched versions |
|---|---|---|
| firefox | < 100.0 | 100.0 |
| firefox esr | < 91.9 | 91.9 |
| thunderbird | < 91.9 | 91.9 |
Firefox behaved slightly differently for already known resources when loading CSS resources involving CSS variables. This could have been used to probe the browser history. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site free