Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade firefox-x11Upgrade firefoxUpgrade thunderbird | Oct 11, 2026 | Aug 24, 2026 |
| Amazon Linux Ami 2 | — | Upgrade thunderbirdUpgrade firefox | Oct 19, 2026 | Oct 19, 2026 |
| Amazon_linux_2023 | — | Upgrade firefox-debuginfoUpgrade firefox-debugsourceUpgrade firefox | Sep 1, 2026 | Aug 18, 2026 |
| Debian | — | Upgrade firefox-esrUpgrade thunderbird | Aug 20, 2026 | Aug 20, 2026 |
| Mfsa2026 74 | — | Upgrade to Mozilla Firefox version 154.0Upgrade to the latest version of Mozilla Firefox | Aug 18, 2026 | Aug 18, 2026 |
| Mfsa2026 76 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox ESR version 140.14 | Aug 18, 2026 | Aug 18, 2026 |
| Mfsa2026 77 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox ESR version 153.1 | Aug 18, 2026 | Aug 18, 2026 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 153.1Upgrade to the latest version of Mozilla Thunderbird | Aug 18, 2026 | Aug 18, 2026 |
| Redhat_linux | — | Upgrade thunderbird-debugsourceUpgrade firefox-debugsourceUpgrade firefox-debuginfoNo solution existsUpgrade firefox | Aug 24, 2026 | Aug 18, 2026 |
| Rocky_linux | — | Upgrade thunderbirdUpgrade firefoxUpgrade thunderbird-debuginfoUpgrade thunderbird-debugsourceUpgrade firefox-debugsourceUpgrade firefox-debuginfoUpgrade firefox-x11 | Aug 26, 2026 | Aug 25, 2026 |
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