CVE-2026-100831

Estado: En análisisAlta (8.8)—

Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

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: 0.25%
Percentil entre todas las CVEs puntuadas: 15
Fecha de la puntuación: 6/10/2026

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.

ExplotaciónT1203 Exploitation for Client Executionexecution85 %
Impacto principalT1059.007 JavaScriptexecution75 %
Impacto secundarioT1005 Data from Local Systemcollection60 %

Use-after-free en manejo de eventos DOM explorable remotamente requiere interacción (UI:R). CVSS:3.1 AV:N/UI:R confirma T1203. El impacto confidencialidad/integridad/disponibilidad (C:H/I:H/A:H) permite ejecución de código JavaScript y acceso a datos del navegador.

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

Restrict Web-Based Content Execution Prevention Behavior Prevention on Endpoint Disable or Remove Feature or Program Application Isolation and Sandboxing Exploit Protection

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Mozilla — Firefox^AI

CWE

CWE-416

Referencias

JSON original (NVD)

Mostrar

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  "id": "CVE-2026-100831",
  "cveTags": [],
  "metrics": {
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      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-100831",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-29T13:12:18.595259Z"
        }
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          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
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        "impactScore": 5.9,
        "exploitabilityScore": 2.8
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  "published": "2026-09-29T13:17:48.350",
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    {
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2067172",
      "source": "security@mozilla.org"
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    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-100/",
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      "url": "https://www.mozilla.org/security/advisories/mfsa2026-101/",
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    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-103/",
      "source": "security@mozilla.org"
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    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-97/",
      "source": "security@mozilla.org"
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      "value": "Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157."
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  "lastModified": "2026-09-30T18:18:13.273",
  "sourceIdentifier": "security@mozilla.org"
}