{
  "id": "CVE-2020-26956",
  "sourceIdentifier": "security@mozilla.org",
  "published": "2020-12-09T01:15:12.957",
  "lastModified": "2020-12-10T17:02:03.177",
  "vulnStatus": "Analyzed",
  "descriptions": [
    {
      "lang": "en",
      "value": "In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5."
    },
    {
      "lang": "es",
      "value": "En algunos casos, al eliminar unos elementos HTML durante el saneamiento mantendr\u00eda los actuales manejadores de eventos SVG y, por lo tanto, conllevar\u00eda a un ataque de tipo XSS. Esta vulnerabilidad afecta a Firefox versiones anteriores a 83, Firefox ESR versiones anteriores a 78.5, y Thunderbird versiones anteriores a 78.5"
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.7
      }
    ],
    "cvssMetricV2": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "2.0",
          "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
          "accessVector": "NETWORK",
          "accessComplexity": "MEDIUM",
          "authentication": "NONE",
          "confidentialityImpact": "NONE",
          "integrityImpact": "PARTIAL",
          "availabilityImpact": "NONE",
          "baseScore": 4.3
        },
        "baseSeverity": "MEDIUM",
        "exploitabilityScore": 8.6,
        "impactScore": 2.9,
        "acInsufInfo": false,
        "obtainAllPrivilege": false,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": true
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "83.0",
              "matchCriteriaId": "9385C808-43DD-4D02-B1A9-89A2E3986DF2"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "78.5",
              "matchCriteriaId": "36160ED9-05B8-4E38-8C67-49EE1738AF8B"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "78.5",
              "matchCriteriaId": "C169EC17-3490-437D-A36B-40C3DE316175"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1666300",
      "source": "security@mozilla.org",
      "tags": [
        "Issue Tracking",
        "Permissions Required",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2020-50/",
      "source": "security@mozilla.org",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2020-51/",
      "source": "security@mozilla.org",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2020-52/",
      "source": "security@mozilla.org",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}