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CVE-2019-11720

Status: ModifiedMedium (6.1)—

Some unicode characters are incorrectly treated as whitespace during the parsing of web content instead of triggering parsing errors. This allows malicious code to then be processed, evading cross-site scripting (XSS) filtering. This vulnerability affects Firefox < 68.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Mozilla — FirefoxOpensuse — Leap

CWEs

References

Raw JSON (NVD)

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  "id": "CVE-2019-11720",
  "cveTags": [],
  "metrics": {
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          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "NONE"
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        "impactScore": 2.9,
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          "integrityImpact": "LOW",
          "userInteraction": "REQUIRED",
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          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
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  "affected": [
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          "versions": [
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              "versionType": "custom"
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  "published": "2019-07-23T14:15:16.140",
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      "description": [
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          "value": "CWE-79"
        }
      ]
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  ],
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      "lang": "en",
      "value": "Some unicode characters are incorrectly treated as whitespace during the parsing of web content instead of triggering parsing errors. This allows malicious code to then be processed, evading cross-site scripting (XSS) filtering. This vulnerability affects Firefox < 68."
    },
    {
      "lang": "es",
      "value": "Algunos caracteres unicode son tratados incorrectamente como espacios en blanco durante el análisis de contenido web en lugar de desencadenar errores de análisis. Esto permite que sea procesado el código malicioso, evadiendo el filtrado de cross-site scripting (XSS). Esta vulnerabilidad afecta a Firefox anteriores a versión 68."
    }
  ],
  "lastModified": "2026-06-17T02:13:30.170",
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