Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154, Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and Thunderbird 153.2.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade thunderbirdUpgrade firefoxUpgrade firefox-x11 | Oct 11, 2026 | Sep 14, 2026 |
| Debian | — | Upgrade firefox-esrUpgrade thunderbird | Sep 21, 2026 | Aug 18, 2026 |
| Mfsa2026 83 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox ESR version 115.40 | Sep 1, 2026 | Sep 1, 2026 |
| Mfsa2026 84 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox ESR version 140.15 | Sep 1, 2026 | Sep 1, 2026 |
| Mfsa2026 85 | — | Upgrade to Mozilla Firefox ESR version 153.2Upgrade to the latest version of Mozilla Firefox | Sep 1, 2026 | Sep 1, 2026 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 153.2Upgrade to the latest version of Mozilla Thunderbird | Sep 1, 2026 | Sep 1, 2026 |
| Oracle_linux | — | Upgrade thunderbirdUpgrade firefoxUpgrade firefox-x11 | Oct 22, 2026 | Aug 18, 2026 |
| Redhat_linux | — | Upgrade firefox-debugsourceNo solution existsUpgrade firefox-x11Upgrade firefoxUpgrade firefox-debuginfoUpgrade thunderbird-debugsourceUpgrade thunderbird-debuginfoUpgrade thunderbird | Sep 10, 2026 | Aug 18, 2026 |
| Rocky_linux | — | Upgrade firefox-debuginfoUpgrade thunderbird-debuginfoUpgrade thunderbird-debugsourceUpgrade firefox-debugsourceUpgrade firefox-x11Upgrade thunderbirdUpgrade firefox | Sep 28, 2026 | Sep 25, 2026 |
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