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CVE-2020-26974

Estado: ModificadaAlta (8.8)—

When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type. This resulted in a heap user-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

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).

Tecnologías afectadas (3)

Mozilla — FirefoxMozilla — Firefox ESRMozilla — Thunderbird

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2020-26974",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 6.8,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8.6,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": true
      }
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    "cvssMetricV31": [
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        "source": "nvd@nist.gov",
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          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "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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  "affected": [
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      "affectedData": [
        {
          "vendor": "Mozilla",
          "product": "Firefox",
          "versions": [
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              "versionType": "custom"
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          "vendor": "Mozilla",
          "product": "Thunderbird",
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  "published": "2021-01-07T14:15:12.000",
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      "tags": [
        "Permissions Required"
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      "source": "security@mozilla.org"
    },
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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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      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type. This resulted in a heap user-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6."
    },
    {
      "lang": "es",
      "value": "Cuando flex-basis fue usada en un contenedor de tabla, un objeto StyleGenericFlexBasis podría haberse convertido incorrectamente en el tipo equivocado.&#xa0;Esto resultó en uso de la memoria previamente liberada de la pila, una corrupción de la memoria y un bloqueo potencialmente explotable.&#xa0;Esta vulnerabilidad afecta a Firefox versiones anteriores a 84, Thunderbird versiones anteriores a 78,6 y Firefox ESR versiones anteriores a 78,6"
    }
  ],
  "lastModified": "2026-06-17T03:08:39.013",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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}