CVE-2025-9184
Memory safety bugs fixed in Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbird 142
CVSS Score
8.1
EPSS Score
0.1%
EPSS Percentile
21th
Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141. 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 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird 140.2.
| Vendor | mozilla |
| Product | firefox |
| Ecosystems | |
| Industries | Technology |
| Published | Aug 19, 2025 |
| Last Updated | Apr 13, 2026 |
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Affected Versions
Mozilla / Firefox
All versions affected Mozilla / Thunderbird
All versions affected References
bugzilla.mozilla.org: https://bugzilla.mozilla.org/buglist.cgi?bug_id=1929482%2C1976376%2C1979163%2C1979955 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-64/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-67/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-70/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-72/
Credits
Paul Bone, Ryan VanderMeulen and the Mozilla Fuzzing Team