CVE-2025-4091
HIGH severity · CVSS 8.1 · Memory corruption
8.1CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityHigh
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Additional information
- NVD record
- https://www.mozilla.org/security/advisories/mfsa2025-28/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-29/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-31/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-32/Advisory
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1951161%2C1952105
- https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html