When reusing existing popups Firefox would have allowed them to cover the fullscreen notification UI, which could have enabled browser spoofing attacks. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Firefox | Mozilla | * | 100.0 (excluding) |
| Firefox_esr | Mozilla | * | 91.9 (excluding) |
| Thunderbird | Mozilla | * | 91.9 (excluding) |