Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade firefox-x11Upgrade thunderbirdUpgrade firefox | Apr 29, 2026 | Apr 27, 2026 |
| Amazon Linux Ami 2 | — | Upgrade thunderbirdUpgrade firefox | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade firefoxUpgrade firefox-debuginfoUpgrade firefox-debugsource | May 19, 2026 | Apr 21, 2026 |
| Debian | — | Upgrade firefox-esrUpgrade thunderbird | Apr 23, 2026 | Apr 23, 2026 |
| Freebsd | — | Upgrade firefox-esrUpgrade thunderbirdUpgrade firefox | Apr 30, 2026 | Apr 28, 2026 |
| Mfsa2026 30 | — | Upgrade to Mozilla Firefox version 150.0 | Apr 23, 2026 | Apr 21, 2026 |
| Mfsa2026 32 | — | Upgrade to Mozilla Firefox ESR version 140.10 | Apr 23, 2026 | Apr 21, 2026 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 140.10 | Apr 23, 2026 | Apr 21, 2026 |
| Oracle_linux | — | Upgrade firefox-x11Upgrade firefoxUpgrade thunderbird | Apr 29, 2026 | Apr 21, 2026 |
| Redhat_linux | — | Upgrade thunderbird-debugsourceUpgrade firefox-debuginfoUpgrade thunderbirdUpgrade firefox-x11Upgrade firefox-debugsourceUpgrade firefoxNo solution existsUpgrade thunderbird-debuginfo | Apr 29, 2026 | Apr 21, 2026 |
| Rocky_linux | — | Upgrade firefox-x11Upgrade thunderbird-debuginfoUpgrade firefox-debugsourceUpgrade thunderbirdUpgrade thunderbird-debugsourceUpgrade firefox-debuginfoUpgrade firefox | May 4, 2026 | Apr 28, 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