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CVE-2026-8959

Estado: AnalizadaCrítica (9.6)—

Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

CVSS

Probabilidad de explotación (EPSS)

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.

UI:R en vector CVSS indica interacción del usuario (abrir fichero/contenido preparado). Sandbox escape + Win32 component permite ejecución de código fuera del sandbox, escalando desde ejecución en el cliente a privilegios del navegador/sistema.

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

Execution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate SoftwareThreat Intelligence ProgramRestrict Web-Based Content

Tecnologías afectadas (2)

Mozilla — FirefoxMozilla — Thunderbird

CWE

Referencias

JSON original (NVD)

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          "role": "CISA Coordinator",
          "options": [
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            },
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    }
  ],
  "lastModified": "2026-06-17T11:04:40.630",
  "configurations": [
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