{
  "document": {
    "category": "security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "publisher": {
      "category": "vendor",
      "contact_details": "support@arista.com",
      "name": "Arista PSIRT",
      "namespace": "https://www.arista.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "Security advisory 155 canonical URL",
        "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24711-security-advisory-0155"
      }
    ],
    "title": "Security Advisory 155",
    "tracking": {
      "current_release_date": "2026-09-17T11:48:12Z",
      "generator": {
        "engine": {
          "name": "Arista Networks SecEng Service CSAF Generator"
        }
      },
      "id": "Arista Networks Security Advisory 155",
      "initial_release_date": "2026-09-17T11:48:12Z",
      "revision_history": [
        {
          "date": "2026-09-17T11:48:12Z",
          "number": "1",
          "summary": "Document created"
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "branches": [
                  {
                    "category": "product_version",
                    "name": "EOS version 4.34.8",
                    "product": {
                      "name": "EOS version 4.34.8",
                      "product_id": "CSAFPID-0"
                    }
                  },
                  {
                    "category": "product_version",
                    "name": "EOS version 4.35.6",
                    "product": {
                      "name": "EOS version 4.35.6",
                      "product_id": "CSAFPID-1"
                    }
                  },
                  {
                    "category": "product_version",
                    "name": "EOS version 1.0.0",
                    "product": {
                      "name": "EOS version 1.0.0",
                      "product_id": "CSAFPID-3"
                    }
                  },
                  {
                    "category": "product_version",
                    "name": "EOS version 4.36.0",
                    "product": {
                      "name": "EOS version 4.36.0",
                      "product_id": "CSAFPID-4"
                    }
                  },
                  {
                    "category": "product_version",
                    "name": "EOS version 4.33.10",
                    "product": {
                      "name": "EOS version 4.33.10",
                      "product_id": "CSAFPID-2"
                    }
                  }
                ],
                "category": "product_name",
                "name": "EOS"
              }
            ],
            "category": "product_family",
            "name": "Software Products"
          }
        ],
        "category": "vendor",
        "name": "Arista Networks, Inc."
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-19655",
      "id": {
        "system_name": "Arista Bug ID",
        "text": "1770194"
      },
      "notes": [
        {
          "category": "description",
          "text": "On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart.",
          "title": "CVE Description"
        },
        {
          "category": "other",
          "text": "In order to be vulnerable to CVE-2026-19655, any of the following conditions must be met:\n\nConfigure \u201c`ip dhcp relay`\u201d with the \u201c`information option`\u201d (Option 82) and at least one helper-address on an interface:\n\nOr\n\nConfigure \u201c`ip dhcp snooping`\u201d with the \u201c`information option`\u201d:\n\nOr\n\nThe DHCP server uses match criteria based on the information option,  configured with \u201c`information option arista-switch`\u201d commands. Below is an example of configuring the DHCP server to match requests containing Arista switch information that identifies Ethernet55/1 and VLAN 100 in DHCP Option 82:",
          "title": "1770194: Required Config for Exploitation"
        }
      ],
      "product_status": {
        "first_affected": [
          "CSAFPID-3"
        ],
        "fixed": [
          "CSAFPID-0",
          "CSAFPID-1",
          "CSAFPID-2",
          "CSAFPID-4"
        ]
      },
      "references": [
        {
          "category": "external",
          "url": "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-19655",
          "summary": "MITRE"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Fixed in EOS version 4.33.10",
          "product_ids": [
            "CSAFPID-2"
          ]
        },
        {
          "category": "vendor_fix",
          "details": "Fixed in EOS version 4.34.8",
          "product_ids": [
            "CSAFPID-0"
          ]
        },
        {
          "category": "vendor_fix",
          "details": "Fixed in EOS version 4.35.6",
          "product_ids": [
            "CSAFPID-1"
          ]
        },
        {
          "category": "vendor_fix",
          "details": "Fixed in EOS version 4.36.0",
          "product_ids": [
            "CSAFPID-4"
          ]
        },
        {
          "category": "none_available",
          "details": "Not fixed in EOS version 1.0.0",
          "product_ids": [
            "CSAFPID-3"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-2",
            "CSAFPID-3",
            "CSAFPID-0",
            "CSAFPID-4",
            "CSAFPID-1"
          ]
        }
      ],
      "title": "CVE-2026-19655"
    }
  ]
}