{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-28806",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-28806",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-06-03T02:45:13.325Z",
    "updatedAt": "2024-09-16T22:55:32.202Z",
    "importedAt": "2026-10-24T01:56:26.894Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "DOM-Based XSS Vulnerability in QTS and QuTS hero",
      "summary": "A DOM-based XSS vulnerability has been reported to affect QNAP NAS running QTS and QuTS hero. If exploited, this vulnerability allows attackers to inject malicious code. This issue affects: QNAP Systems Inc. QTS versions prior to 4.5.3.1652 Build 20210428. QNAP Systems Inc. QuTS hero versions prior to h4.5.2.1638 Build 20210414. QNAP Systems Inc. QuTScloud versions prior to c4.5.5.1656 Build 20210503. This issue does not affect: QNAP Systems Inc. QTS 4.3.6; 4.3.3.",
      "affected": [
        {
          "vendor": "QNAP Systems Inc.",
          "product": "QTS",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "4.5.3.1652 Build 20210428"
            },
            {
              "version": "4.3.6",
              "status": "unaffected"
            },
            {
              "version": "4.3.3",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "QNAP Systems Inc.",
          "product": "QuTS hero",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "h4.5.2.1638 Build 20210414"
            }
          ]
        },
        {
          "vendor": "QNAP Systems Inc.",
          "product": "QuTScloud",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "c4.5.5.1656 Build 20210503"
            }
          ]
        }
      ]
    }
  }
}