{
  "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-2026-21910",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-21910",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-01-15T20:23:29.682Z",
    "updatedAt": "2026-01-15T20:51:57.933Z",
    "importedAt": "2026-10-24T01:58:02.025Z",
    "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: EX4k Series, QFX5k Series: In an EVPN-VXLAN configuration link flaps cause Inter-VNI traffic drop",
      "summary": "An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on EX4k Series and QFX5k Series platforms allows an unauthenticated network-adjacent attacker flapping an interface to cause traffic between VXLAN Network Identifiers (VNIs) to drop, leading to a Denial of Service (DoS).\n\nOn all EX4k and QFX5k platforms, a link flap in an\n\nEVPN-VXLAN configuration Link Aggregation Group (LAG)\nresults in Inter-VNI traffic dropping when there are multiple load-balanced next-hop routes for the same destination.\n\nThis issue is only applicable to systems that support EVPN-VXLAN Virtual Port-Link Aggregation Groups (VPLAG), such as the QFX5110, QFX5120, QFX5200, EX4100, EX4300, EX4400, and EX4650.\n\nService can only be restored by restarting the affected FPC via the 'request chassis fpc restart slot <slot-number>' command.\n\nThis issue affects Junos OS \n\non EX4k and QFX5k Series: \n\n\n\n  *  all versions before 21.4R3-S12, \n  *  all versions of 22.2\n  *  from 22.4 before 22.4R3-S8, \n  *  from 23.2 before 23.2R2-S5, \n  *  from 23.4 before 23.4R2-S5, \n  *  from 24.2 before 24.2R2-S3,\n  *  from 24.4 before 24.4R2.",
      "affected": [
        {
          "vendor": "Juniper Networks",
          "product": "Junos OS",
          "platforms": [
            "EX4k Series",
            "QFX5k Series"
          ],
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "21.4R3-S12"
            },
            {
              "version": "22.2",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "22.2*"
            },
            {
              "version": "22.4",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "22.4R3-S8"
            },
            {
              "version": "23.2",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "23.2R2-S5"
            },
            {
              "version": "23.4",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "23.4R2-S5"
            },
            {
              "version": "24.2",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "24.2R2-S3"
            },
            {
              "version": "24.4",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "24.4R2"
            }
          ]
        }
      ]
    }
  }
}