Description
Memory safety bugs present in Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbird 142. 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 143, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.
References (7)
Core 7
Core References
Issue Tracking
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1938220%2C1980730%2C1981280%2C1981283%2C1984505%2C1985067
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-73/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-75/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-77/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-78/
Scores
CVSS v3
8.8
EPSS
0.0007
EPSS Percentile
21.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-119
Status
published
Products (8)
mozilla/firefox
< 140.3.0
mozilla/firefox
< 143.0
Mozilla/Firefox
140.3 - 140.*
Mozilla/Firefox
143
mozilla/thunderbird
< 140.3.0
mozilla/thunderbird
< 143.0
Mozilla/Thunderbird
140.3 - 140.*
Mozilla/Thunderbird
143
Published
Sep 16, 2025
Tracked Since
Feb 18, 2026