CVE-2026-5731
Estado: ModificadaCrítica (9.8)—
Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2, Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.61%
- Percentil entre todas las CVEs puntuadas: 47
- Fecha de la puntuación: 4/10/2026
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
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1059Command and Scripting Interpreterexecution80 %
Vector CVSS AV:N/PR:N/UI:N indica red sin privilegios. Memory safety bugs (CWE-119, CWE-787) en navegador/cliente permiten ejecución de código arbitrario remoto sin interacción del usuario.
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-119
- CWE-787
Referencias
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2021894%2C2022225%2C2022252%2C2022294%2C2023007%2C2023130%2C2023191%2C2023364%2C2023829%2C2024074%2C2024417%2C2024433%2C2024436%2C2024437%2C2024453%2C2024461%2C2024462%2C2024472%2C2024474%2C2024477%2C2025364%2C2025401%2C2025402%2C2025472%2C2026287%2C2026299%2C2026305%2C2026426
- https://www.mozilla.org/security/advisories/mfsa2026-25/
- https://www.mozilla.org/security/advisories/mfsa2026-26/
- https://www.mozilla.org/security/advisories/mfsa2026-27/
- https://www.mozilla.org/security/advisories/mfsa2026-28/
- https://www.mozilla.org/security/advisories/mfsa2026-29/
- https://access.redhat.com/errata/RHSA-2026:11805
- https://access.redhat.com/errata/RHSA-2026:11813
- https://access.redhat.com/errata/RHSA-2026:12264
- https://access.redhat.com/errata/RHSA-2026:13342
- https://access.redhat.com/errata/RHSA-2026:13412
- https://access.redhat.com/errata/RHSA-2026:13533
- https://access.redhat.com/errata/RHSA-2026:13582
- https://access.redhat.com/errata/RHSA-2026:13583
- https://access.redhat.com/errata/RHSA-2026:13596
- https://access.redhat.com/errata/RHSA-2026:13600
- https://access.redhat.com/errata/RHSA-2026:13665
- https://access.redhat.com/errata/RHSA-2026:13682
- https://access.redhat.com/errata/RHSA-2026:13683
- https://access.redhat.com/errata/RHSA-2026:13922
- https://access.redhat.com/errata/RHSA-2026:13977
- https://access.redhat.com/errata/RHSA-2026:14223
- https://access.redhat.com/errata/RHSA-2026:14303
- https://access.redhat.com/errata/RHSA-2026:15889
- https://access.redhat.com/errata/RHSA-2026:7671
- https://access.redhat.com/errata/RHSA-2026:7672
- https://access.redhat.com/errata/RHSA-2026:8052
- https://access.redhat.com/errata/RHSA-2026:8459
- https://access.redhat.com/errata/RHSA-2026:9345
- https://access.redhat.com/errata/RHSA-2026:9638
- https://access.redhat.com/security/cve/CVE-2026-5731
- https://bugzilla.redhat.com/show_bug.cgi?id=2455901
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5731.json
JSON original (NVD)
Mostrar
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