Description
Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9. 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 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbird 128.10.
Affected products
mozilla: firefox; mozilla: thunderbird
References6
- www.mozilla.org/security/advisories/mfsa2025-28/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-29/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-31/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-32/ Vendor Advisory
- bugzilla.mozilla.org/buglist.cgi?bug_id=1951161%2C1952105 Broken Link
- lists.debian.org/debian-lts-announce/2025/05/msg00024.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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