{
  "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-2021-31363",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-31363",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-10-19T18:16:50.581Z",
    "updatedAt": "2024-09-16T16:23:31.512Z",
    "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": "Junos OS and Junos OS Evolved: Receipt of a specific LDP message will cause a Denial of Service",
      "summary": "In an MPLS P2MP environment a Loop with Unreachable Exit Condition vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause high load on RPD which in turn may lead to routing protocol flaps. If a system with sensor-based-stats enabled receives a specific LDP FEC this can lead to the above condition. Continued receipted of such an LDP FEC will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS 19.2 version 19.2R2 and later versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S2; 20.1 versions prior to 20.1R2-S1, 20.1R3; 20.2 versions prior to 20.2R2-S1, 20.2R3; 20.3 versions prior to 20.3R1-S2, 20.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 19.2R2. Juniper Networks Junos OS Evolved All versions prior to 20.1R2-S3-EVO; 20.3 versions prior to 20.3R1-S2-EVO.",
      "affected": [
        {
          "vendor": "Juniper Networks",
          "product": "Junos OS",
          "versions": [
            {
              "version": "unspecified",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "19.2R2"
            },
            {
              "version": "19.2R2",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.2*",
              "changes": [
                {
                  "at": "19.2R3-S3",
                  "status": "unaffected"
                }
              ]
            },
            {
              "version": "19.3",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.3R2-S6, 19.3R3-S2"
            },
            {
              "version": "19.4",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.4R1-S4, 19.4R2-S4, 19.4R3-S2"
            },
            {
              "version": "20.1",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.1R2-S1, 20.1R3"
            },
            {
              "version": "20.2",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.2R2-S1, 20.2R3"
            },
            {
              "version": "20.3",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.3R1-S2, 20.3R2"
            }
          ]
        },
        {
          "vendor": "Juniper Networks",
          "product": "Junos OS Evolved",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.1R2-S3-EVO"
            },
            {
              "version": "20.3",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.3R1-S2-EVO"
            }
          ]
        }
      ]
    }
  }
}