CVE-2025-4919

Description

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.

PUBLISHED Reserved 2025-05-17 | Published 2025-05-17 | Updated 2026-04-13 | Assigner mozilla

Product status

Credits

Manfred Paul working with Trend Micro's Zero Day Initiative

References

lists.debian.org/debian-lts-announce/2025/05/msg00046.html

lists.debian.org/debian-lts-announce/2025/05/msg00024.html

bugzilla.mozilla.org/show_bug.cgi?id=1966614

www.mozilla.org/security/advisories/mfsa2025-36/

www.mozilla.org/security/advisories/mfsa2025-37/

www.mozilla.org/security/advisories/mfsa2025-38/

www.mozilla.org/security/advisories/mfsa2025-40/

www.mozilla.org/security/advisories/mfsa2025-41/

cve.org (CVE-2025-4919)

nvd.nist.gov (CVE-2025-4919)

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