Description
Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. 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 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Affected products
mozilla: firefox; mozilla: thunderbird
References7
- www.mozilla.org/security/advisories/mfsa2025-42/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-44/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-45/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-46/ Vendor Advisory
- bugzilla.mozilla.org/buglist.cgi?bug_id=1950136%2C1958121%2C196… Broken Link
- lists.debian.org/debian-lts-announce/2025/05/msg00043.html
- lists.debian.org/debian-lts-announce/2025/05/msg00046.html
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 44 · as of 7 November 2026
- CWE
- CWE-119
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