A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level documents process instead of the intended frame, potentially enabling a sandbox escape. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
Weakness
The product does not properly compartmentalize or isolate functionality, processes, or resources that require different privilege levels, rights, or permissions.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Firefox | Mozilla | * | 115.23 (excluding) |
| Firefox | Mozilla | * | 138.0 (excluding) |
| Firefox | Mozilla | 128.0 (including) | 128.10 (excluding) |
| Thunderbird | Mozilla | * | 128.10.0 (excluding) |
| Thunderbird | Mozilla | * | 138.0 (excluding) |
| Red Hat Enterprise Linux 10 | RedHat | firefox-0:128.10.0-1.el10_0 | * |
| Red Hat Enterprise Linux 10 | RedHat | thunderbird-0:128.10.0-1.el10_0 | * |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | RedHat | firefox-0:128.10.0-1.el7_9 | * |
| Red Hat Enterprise Linux 8 | RedHat | firefox-0:128.10.0-1.el8_10 | * |
| Red Hat Enterprise Linux 8 | RedHat | thunderbird-0:128.10.0-1.el8_10 | * |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | RedHat | firefox-0:128.10.0-1.el8_2 | * |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | RedHat | thunderbird-0:128.10.0-1.el8_2 | * |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | RedHat | firefox-0:128.10.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | RedHat | thunderbird-0:128.10.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.4 Telecommunications Update Service | RedHat | firefox-0:128.10.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.4 Telecommunications Update Service | RedHat | thunderbird-0:128.10.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions | RedHat | firefox-0:128.10.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions | RedHat | thunderbird-0:128.10.0-1.el8_4 | * |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | RedHat | firefox-0:128.10.0-1.el8_6 | * |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | RedHat | thunderbird-0:128.10.0-1.el8_6 | * |
| Red Hat Enterprise Linux 8.6 Telecommunications Update Service | RedHat | firefox-0:128.10.0-1.el8_6 | * |
| Red Hat Enterprise Linux 8.6 Telecommunications Update Service | RedHat | thunderbird-0:128.10.0-1.el8_6 | * |
| Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions | RedHat | firefox-0:128.10.0-1.el8_6 | * |
| Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions | RedHat | thunderbird-0:128.10.0-1.el8_6 | * |
| Red Hat Enterprise Linux 8.8 Extended Update Support | RedHat | firefox-0:128.10.0-1.el8_8 | * |
| Red Hat Enterprise Linux 8.8 Extended Update Support | RedHat | thunderbird-0:128.10.0-1.el8_8 | * |
| Red Hat Enterprise Linux 9 | RedHat | firefox-0:128.10.0-1.el9_5 | * |
| Red Hat Enterprise Linux 9 | RedHat | thunderbird-0:128.10.0-1.el9_5 | * |
| Red Hat Enterprise Linux 9 | RedHat | firefox-0:128.10.0-1.el9_6 | * |
| Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions | RedHat | firefox-0:128.10.0-1.el9_0 | * |
| Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions | RedHat | thunderbird-0:128.10.0-1.el9_0 | * |
| Red Hat Enterprise Linux 9.2 Extended Update Support | RedHat | firefox-0:128.10.0-1.el9_2 | * |
| Red Hat Enterprise Linux 9.2 Extended Update Support | RedHat | thunderbird-0:128.10.0-1.el9_2 | * |
| Red Hat Enterprise Linux 9.4 Extended Update Support | RedHat | firefox-0:128.10.0-1.el9_4 | * |
| Red Hat Enterprise Linux 9.4 Extended Update Support | RedHat | thunderbird-0:128.10.0-1.el9_4 | * |
| Firefox | Ubuntu | focal | * |
| Firefox | Ubuntu | upstream | * |
| Mozjs102 | Ubuntu | esm-apps/noble | * |
| Mozjs102 | Ubuntu | jammy | * |
| Mozjs102 | Ubuntu | noble | * |
| Mozjs115 | Ubuntu | noble | * |
| Mozjs115 | Ubuntu | oracular | * |
| Mozjs115 | Ubuntu | plucky | * |
| Mozjs52 | Ubuntu | esm-infra/bionic | * |
| Mozjs52 | Ubuntu | focal | * |
| Mozjs68 | Ubuntu | esm-infra/focal | * |
| Mozjs68 | Ubuntu | focal | * |
| Mozjs78 | Ubuntu | jammy | * |
| Mozjs91 | Ubuntu | jammy | * |
| Thunderbird | Ubuntu | focal | * |
| Thunderbird | Ubuntu | jammy | * |
| Thunderbird | Ubuntu | upstream | * |
Potential Mitigations
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1958350
- https://www.mozilla.org/security/advisories/mfsa2025-28/
- https://www.mozilla.org/security/advisories/mfsa2025-29/
- https://www.mozilla.org/security/advisories/mfsa2025-30/
- https://www.mozilla.org/security/advisories/mfsa2025-31/
- https://www.mozilla.org/security/advisories/mfsa2025-32/
- https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html