{
  "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-2021-28511",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-28511",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2022-08-05T16:47:31.584Z",
    "updatedAt": "2026-06-02T14:07:52.943Z",
    "importedAt": "2026-10-24T01:56:26.894Z",
    "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": "This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass.  The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches t ...",
      "summary": "This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass. The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches the packet flow. This could allow a host with an IP address in a range that matches the range allowed by a NAT ACL and a range denied by a Security ACL to be forwarded incorrectly as it should have been denied by the Security ACL. This can enable an ACL bypass.",
      "affected": [
        {
          "vendor": "Arista Networks",
          "product": "EOS",
          "versions": [
            {
              "version": "4.24.0",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "4.24.9"
            },
            {
              "version": "4.25.0",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "4.25.8"
            },
            {
              "version": "4.26.0",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "4.26.5"
            },
            {
              "version": "4.27.0",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "4.27.3"
            }
          ]
        }
      ]
    }
  }
}