HtmlSanitizer before 9.2.1039 XSS via SanitizeDom Body and HTML Attributes

{
  "id": "d81f75ca6634403eb8f70c125289d59b882694f16a52c2945447accf743d59e4",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-116538",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "HtmlSanitizer before 9.2.1039 XSS via SanitizeDom Body and HTML Attributes",
    "summary": "HtmlSanitizer before 9.2.1039 and 10.0 prereleases before 10.0.1037-beta contains a cross-site scripting vulnerability because SanitizeDom(string) never sanitizes attributes on the html and body wrapper elements. Attackers can supply input with a second body or html tag carrying event handlers like onload, executing script when applications render serialized document or body outer HTML.",
    "evidence": "cve:CVE-2026-116538",
    "products": [
      {
        "name": {
          "value": "HtmlSanitizer",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-116538",
      "aliases": [
        "CVE-2026-116538"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 2.3,
            "attackVector": "NETWORK",
            "baseSeverity": "LOW",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE"
          }
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "CHANGED",
            "version": "3.1",
            "baseScore": 4.7,
            "attackVector": "NETWORK",
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "integrityImpact": "LOW",
            "userInteraction": "REQUIRED",
            "attackComplexity": "HIGH",
            "availabilityImpact": "NONE",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "LOW"
          }
        }
      ],
      "affected": [
        {
          "repo": "https://github.com/mganss/HtmlSanitizer",
          "vendor": "mganss",
          "product": "HtmlSanitizer",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "9.2.1039",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "10.0.0-beta",
              "lessThan": "10.0.1037-beta",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:nuget/HtmlSanitizer",
          "packageName": "HtmlSanitizer",
          "collectionURL": "https://www.nuget.org/packages/HtmlSanitizer",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-26T14:59:38.815Z",
      "provider": "cve",
      "references": [
        "https://github.com/mganss/HtmlSanitizer/commit/96afbc818e64de7571ea17954a05d523e819c56f",
        "https://github.com/mganss/HtmlSanitizer/commit/ab626e7a4f2893f7e9ec0a72779ae19c5ec439a7",
        "https://github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L456-L465",
        "https://github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L555-L583",
        "https://joshua.hu/htmlsanitizer-sanitizedom-body-html-attribute-bypass",
        "https://github.com/mganss/HtmlSanitizer/releases/tag/v9.2.1039",
        "https://github.com/mganss/HtmlSanitizer/releases/tag/v10.0.1037-beta",
        "https://github.com/mganss/HtmlSanitizer",
        "https://www.vulncheck.com/advisories/htmlsanitizer-before-9.2.1039-xss-via-sanitizedom-body-and-html-attributes"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
          "shortName": "VulnCheck",
          "dateUpdated": "2026-10-26T14:59:38.815Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-116538",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 314037,
  "published_at": "2026-10-26T14:59:38.815+00:00"
}