{
  "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-2021-39181",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-39181",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-09-01T19:45:11.000Z",
    "updatedAt": "2024-08-04T01:58:18.230Z",
    "importedAt": "2026-10-24T01:56:32.228Z",
    "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": "Unsafe Deserialization of User Data Using XStream",
      "summary": "OpenOlat is a web-based learning management system (LMS). Prior to version 15.3.18, 15.5.3, and 16.0.0, using a prepared import XML file (e.g. a course) any class on the Java classpath can be instantiated, including spring AOP bean factories. This can be used to execute code arbitrary code by the attacker. The attack requires an OpenOlat user account with the authoring role. It can not be exploited by unregistered users. The problem is fixed in versions 15.3.18, 15.5.3, and 16.0.0. There are no known workarounds aside from upgrading.",
      "affected": [
        {
          "vendor": "OpenOLAT",
          "product": "OpenOLAT",
          "versions": [
            {
              "version": "< 15.3.18",
              "status": "affected"
            },
            {
              "version": ">= 15.4.0, < 15.5.3",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}