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CVE-2026-65902

Full vulnerability record from the local CVENow database.

Description

DOMPurify before 3.4.7 passes direct references to the module-level DEFAULT_ALLOWED_TAGS and DEFAULT_ALLOWED_ATTR sets to the uponSanitizeElement and uponSanitizeAttribute hooks via data.allowedTags / data.allowedAttributes when sanitize is called without an explicit cfg.ALLOWED_TAGS / cfg.ALLOWED_ATTR array. A hook that mutates these fields permanently widens the default allow-lists for the lifetime of the DOMPurify instance, so all subsequent default-config sanitize calls inherit the widened defaults and attacker payloads using the poisoned tag/attribute name survive sanitization. removeAllHooks(), clearConfig(), and passing a fresh cfg do not recover the state; only constructing a new DOMPurify instance does.

Severity
MEDIUM
CVSS score
5.3 (v4.0)
Vulnerability status
Modified
Source identifier
Published
2026-07-23 14:18:05.453000
Last modified
2026-10-29 21:17:29.723000
View original CVE JSON
{
  "id": "CVE-2026-65902",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-23T14:18:05.453",
  "lastModified": "2026-10-29T21:17:29.723",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "DOMPurify before 3.4.7 passes direct references to the module-level DEFAULT_ALLOWED_TAGS and DEFAULT_ALLOWED_ATTR sets to the uponSanitizeElement and uponSanitizeAttribute hooks via data.allowedTags / data.allowedAttributes when sanitize is called without an explicit cfg.ALLOWED_TAGS / cfg.ALLOWED_ATTR array. A hook that mutates these fields permanently widens the default allow-lists for the lifetime of the DOMPurify instance, so all subsequent default-config sanitize calls inherit the widened defaults and attacker payloads using the poisoned tag/attribute name survive sanitization. removeAllHooks(), clearConfig(), and passing a fresh cfg do not recover the state; only constructing a new DOMPurify instance does."
    },
    {
      "lang": "es",
      "value": "DOMPurify antes de la versión 3.4.7 (versiones afectadas menor o igual que 3.4.5) pasa referencias directas a los conjuntos DEFAULT_ALLOWED_TAGS y DEFAULT_ALLOWED_ATTR a nivel de módulo a los hooks uponSanitizeElement y uponSanitizeAttribute a través de data.allowedTags / data.allowedAttributes cuando se llama a sanitize sin un array explícito cfg.ALLOWED_TAGS / cfg.ALLOWED_ATTR. Un hook que muta estos campos amplía permanentemente las listas de permitidos predeterminadas durante la vida útil de la instancia de DOMPurify, por lo que todas las llamadas posteriores a sanitize con configuración predeterminada heredan los valores predeterminados ampliados y las cargas útiles del atacante que utilizan el nombre de etiqueta/atributo envenenado sobreviven a la sanitización. removeAllHooks(), clearConfig() y pasar una nueva cfg no recuperan el estado; solo la construcción de una nueva instancia de DOMPurify lo hace."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "cure53",
          "product": "DOMPurify",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/dompurify",
          "versions": [
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              "version": "0",
              "lessThan": "3.4.7",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "3.4.7",
              "versionType": "semver",
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            }
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        }
      ]
    }
  ],
  "metrics": {
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          "confidentialityRequirement": "NOT_DEFINED",
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          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
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          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
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    ],
    "cvssMetricV31": [
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    "ssvcV203": [
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          "id": "CVE-2026-65902",
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  ],
  "configurations": [
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  "references": [
    {
      "url": "https://github.com/cure53/DOMPurify/commit/7996f1dc78eb8b7922388aed75d94a9f8fad9a36",
      "source": "[email protected]",
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        "Patch"
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      "url": "https://www.vulncheck.com/advisories/dompurify-before-hook-mutation-pollution-via-allowedtags",
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}