Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
CVSS Details
- CVSS 3.1 Base Score: 8.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade firefox-debuginfoUpgrade firefoxUpgrade firefox-debugsource | Sep 1, 2026 | Aug 18, 2026 |
| Debian | — | Upgrade thunderbirdUpgrade firefox-esr | Aug 20, 2026 | Aug 20, 2026 |
| Mfsa2026 74 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox version 154.0 | 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 Mozilla Firefox ESR version 153.1Upgrade to the latest version of Mozilla Firefox | 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 | — | No solution existsUpgrade thunderbird-debuginfoUpgrade firefox-x11Upgrade firefox-debugsourceUpgrade firefoxUpgrade firefox-debuginfoUpgrade thunderbirdUpgrade thunderbird-debugsource | Aug 20, 2026 | Aug 18, 2026 |
| Rocky_linux | — | Upgrade firefox-debugsourceUpgrade firefox-debuginfoUpgrade thunderbird-debuginfoUpgrade thunderbirdUpgrade firefox-x11Upgrade thunderbird-debugsourceUpgrade firefox | Aug 26, 2026 | Aug 25, 2026 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub