CVE-2025-4919
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.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Puntuación base: 8.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 8.63%
- Percentil entre todas las CVEs puntuadas: 95
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1203Exploitation for Client Executionexecution90 % - Impacto principal
T1059Command and Scripting Interpreterexecution75 % - Impacto secundario
T1005Data from Local Systemcollection70 %
UI:R indica interacción del usuario (abrir archivo/archivo adjunto); out-of-bounds en JavaScript permite ejecución de código arbitrario y lectura de memoria en navegador del cliente.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (2)
CWE
- CWE-125, CWE-787
Referencias
- https://bugzilla.mozilla.org/show_bug.cgi?id=1966614
- https://www.mozilla.org/security/advisories/mfsa2025-36/
- https://www.mozilla.org/security/advisories/mfsa2025-37/
- https://www.mozilla.org/security/advisories/mfsa2025-38/
- https://www.mozilla.org/security/advisories/mfsa2025-40/
- https://www.mozilla.org/security/advisories/mfsa2025-41/
- https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html
JSON original (NVD)
Mostrar
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