FKIE_CVE-2020-26293

Vulnerability from fkie_nvd - Published: 2021-01-04 19:15 - Updated: 2026-06-17 03:08
Severity
6.1 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N
6.1 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Summary
HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. In HtmlSanitizer before version 5.0.372, there is a possible XSS bypass if style tag is allowed. If you have explicitly allowed the `<style>` tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the `<style>` tag so there is no risk if you have not explicitly allowed the `<style>` tag. The problem has been fixed in version 5.0.372.
References
security-advisories@github.comhttps://github.com/mganss/HtmlSanitizer/commit/a3a7602a44d4155d51ec0fbbedc2a49e9c7e2eb8Patch, Third Party Advisory
security-advisories@github.comhttps://github.com/mganss/HtmlSanitizer/releases/tag/v5.0.372Release Notes, Third Party Advisory
security-advisories@github.comhttps://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-8j9v-h2vp-2hhvThird Party Advisory
security-advisories@github.comhttps://www.nuget.org/packages/HtmlSanitizer/Product, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/mganss/HtmlSanitizer/commit/a3a7602a44d4155d51ec0fbbedc2a49e9c7e2eb8Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/mganss/HtmlSanitizer/releases/tag/v5.0.372Release Notes, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-8j9v-h2vp-2hhvThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.nuget.org/packages/HtmlSanitizer/Product, Third Party Advisory
Impacted products
Vendor Product Version
htmlsanitizer_project htmlsanitizer *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "HtmlSanitizer",
          "vendor": "mganss",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.0.372"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:htmlsanitizer_project:htmlsanitizer:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "FCB9D50C-682F-4B40-96E0-D15A1BE2A02F",
              "versionEndExcluding": "5.0.372",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. In HtmlSanitizer before version 5.0.372, there is a possible XSS bypass if style tag is allowed. If you have explicitly allowed the `\u003cstyle\u003e` tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the `\u003cstyle\u003e` tag so there is no risk if you have not explicitly allowed the `\u003cstyle\u003e` tag. The problem has been fixed in version 5.0.372."
    },
    {
      "lang": "es",
      "value": "HtmlSanitizer es una biblioteca .NET para limpiar fragmentos HTML y documentos de construcciones que pueden conllevar a ataques de tipo XSS.\u0026#xa0;En HtmlSanitizer versiones anteriores a 5.0.372, se presenta una posible omisi\u00f3n de XSS si la etiqueta de estilo es permitida.\u0026#xa0;Si ha permitido expl\u00edcitamente la etiqueta \"(style)\", un atacante podr\u00eda crear HTML que incluya un script despu\u00e9s de pasar a trav\u00e9s del sanitizador.\u0026#xa0;La configuraci\u00f3n predeterminada no permite la etiqueta \"(style)\", por lo que no existe riesgo si no ha permitido expl\u00edcitamente la etiqueta \"(style)\".\u0026#xa0;El problema ha sido corregido en la versi\u00f3n 5.0.372."
    }
  ],
  "id": "CVE-2020-26293",
  "lastModified": "2026-06-17T03:08:00.980",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "MEDIUM",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "confidentialityImpact": "NONE",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 8.6,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": true
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 4.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.7,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-01-04T19:15:14.970",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/mganss/HtmlSanitizer/commit/a3a7602a44d4155d51ec0fbbedc2a49e9c7e2eb8"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "url": "https://github.com/mganss/HtmlSanitizer/releases/tag/v5.0.372"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-8j9v-h2vp-2hhv"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Product",
        "Third Party Advisory"
      ],
      "url": "https://www.nuget.org/packages/HtmlSanitizer/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/mganss/HtmlSanitizer/commit/a3a7602a44d4155d51ec0fbbedc2a49e9c7e2eb8"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "url": "https://github.com/mganss/HtmlSanitizer/releases/tag/v5.0.372"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-8j9v-h2vp-2hhv"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Product",
        "Third Party Advisory"
      ],
      "url": "https://www.nuget.org/packages/HtmlSanitizer/"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-74"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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