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CVE-2026-8957

Estado: ModificadaAlta (8.8)—

Privilege escalation in the Enterprise Policies 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 indica interacción del usuario (abrir fichero o contenido preparado); acceso de red sin privilegios + escalada de privilegios en Enterprise Policies sugiere ejecución en el cliente con impacto de elevación de privilegios.

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

Application Isolation and SandboxingExploit ProtectionUpdate SoftwareThreat Intelligence ProgramExecution Prevention

Tecnologías afectadas (2)

Mozilla — FirefoxMozilla — Thunderbird

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-8957",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-8957",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-20T03:55:29.107431Z"
        }
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    "cvssMetricV31": [
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
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          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
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      "affectedData": [
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  "published": "2026-05-19T14:16:52.057",
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      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2033850",
      "tags": [
        "Permissions Required"
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      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-46/",
      "tags": [
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    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-48/",
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      "source": "security@mozilla.org"
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      "tags": [
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      "source": "security@mozilla.org"
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      "tags": [
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      "source": "security@mozilla.org"
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  "weaknesses": [
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    {
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      "value": "Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11."
    }
  ],
  "lastModified": "2026-06-17T11:04:40.357",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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