{
  "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-2020-1900",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2020-1900",
    "idYear": 2020,
    "status": "PUBLISHED",
    "publishedAt": "2021-03-11T00:55:20.000Z",
    "updatedAt": "2024-08-04T06:54:00.541Z",
    "importedAt": "2026-10-24T01:56:17.081Z",
    "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": null,
      "summary": "When unserializing an object with dynamic properties HHVM needs to pre-reserve the full size of the dynamic property array before inserting anything into it. Otherwise the array might resize, invalidating previously stored references. This pre-reservation was not occurring in HHVM prior to v4.32.3, between versions 4.33.0 and 4.56.0, 4.57.0, 4.58.0, 4.58.1, 4.59.0, 4.60.0, 4.61.0, 4.62.0.",
      "affected": [
        {
          "vendor": "Facebook",
          "product": "HHVM",
          "versions": [
            {
              "version": "4.62.1",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.62.0",
              "status": "affected"
            },
            {
              "version": "4.61.1",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.61.0",
              "status": "affected"
            },
            {
              "version": "4.60.1",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.60.0",
              "status": "affected"
            },
            {
              "version": "4.59.1",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.59.0",
              "status": "affected"
            },
            {
              "version": "4.58.2",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.58.0",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.57.1",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.57.0",
              "status": "affected"
            },
            {
              "version": "4.56.1",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.33.0",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "4.32.3",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "4.32.3"
            }
          ]
        }
      ]
    }
  }
}