CVE-2025-4919
HIGH severity · CVSS 8.8 · Out-of-bounds read
8.8CVSS HIGH
Summary
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)6%
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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/mfsa2025-36/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-37/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-38/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-40/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-41/Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1966614
- https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html