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.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Firefox | Mozilla | * | 100.0 (excluding) |
| Firefox_esr | Mozilla | * | 91.9 (excluding) |
| Thunderbird | Mozilla | * | 91.9 (excluding) |
| Red Hat Enterprise Linux 7 | RedHat | firefox-0:91.9.0-1.el7_9 | * |
| Red Hat Enterprise Linux 7 | RedHat | thunderbird-0:91.9.0-3.el7_9 | * |
| Red Hat Enterprise Linux 8 | RedHat | firefox-0:91.9.0-1.el8_5 | * |
| Red Hat Enterprise Linux 8 | RedHat | thunderbird-0:91.9.0-3.el8_5 | * |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | RedHat | firefox-0:91.9.0-1.el8_1 | * |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | RedHat | thunderbird-0:91.9.0-3.el8_1 | * |
| Red Hat Enterprise Linux 8.2 Extended Update Support | RedHat | firefox-0:91.9.0-1.el8_2 | * |
| Red Hat Enterprise Linux 8.2 Extended Update Support | RedHat | thunderbird-0:91.9.0-3.el8_2 | * |
| Red Hat Enterprise Linux 8.4 Extended Update Support | RedHat | firefox-0:91.9.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.4 Extended Update Support | RedHat | thunderbird-0:91.9.0-3.el8_4 | * |
| Red Hat Enterprise Linux 9 | RedHat | thunderbird-0:91.9.0-3.el9_0 | * |
| Red Hat Enterprise Linux 9 | RedHat | firefox-0:91.9.0-1.el9_0 | * |
| Firefox | Ubuntu | bionic | * |
| Firefox | Ubuntu | focal | * |
| Firefox | Ubuntu | impish | * |
| Firefox | Ubuntu | trusty | * |
| Firefox | Ubuntu | upstream | * |
| Firefox | Ubuntu | xenial | * |
| Mozjs38 | Ubuntu | bionic | * |
| Mozjs38 | Ubuntu | esm-apps/bionic | * |
| Mozjs38 | Ubuntu | upstream | * |
| Mozjs52 | Ubuntu | bionic | * |
| Mozjs52 | Ubuntu | esm-apps/focal | * |
| Mozjs52 | Ubuntu | esm-infra/bionic | * |
| Mozjs52 | Ubuntu | focal | * |
| Mozjs52 | Ubuntu | upstream | * |
| Mozjs68 | Ubuntu | focal | * |
| Mozjs68 | Ubuntu | upstream | * |
| Mozjs78 | Ubuntu | esm-apps/jammy | * |
| Mozjs78 | Ubuntu | impish | * |
| Mozjs78 | Ubuntu | jammy | * |
| Mozjs78 | Ubuntu | kinetic | * |
| Mozjs78 | Ubuntu | lunar | * |
| Mozjs78 | Ubuntu | upstream | * |
| Mozjs91 | Ubuntu | jammy | * |
| Mozjs91 | Ubuntu | upstream | * |
| Thunderbird | Ubuntu | bionic | * |
| Thunderbird | Ubuntu | devel | * |
| Thunderbird | Ubuntu | focal | * |
| Thunderbird | Ubuntu | impish | * |
| Thunderbird | Ubuntu | jammy | * |
| Thunderbird | Ubuntu | kinetic | * |
| Thunderbird | Ubuntu | lunar | * |
| Thunderbird | Ubuntu | mantic | * |
| Thunderbird | Ubuntu | noble | * |
| Thunderbird | Ubuntu | trusty | * |
| Thunderbird | Ubuntu | upstream | * |
| Thunderbird | Ubuntu | xenial | * |