CVE-2026-120979 (GCVE-0-2026-120979)

Vulnerability from cvelistv5 – Published: 2026-11-10 20:09 – Updated: 2026-11-10 20:09
VLAI
Title
Security Advisory 0212
Summary
This vulnerability affects customers using Arista Pathfinder for WAN path selection with Border Gateway Protocol-Link State (BGP-LS) configured for Dynamic Path Selection (DPS). On affected platforms running Arista EOS with BGP-LS configured for DPS, an attacker who has established an authenticated BGP-LS session with the device can send a specially crafted BGP packet to cause incorrect WAN path selection and disrupt traffic forwarding.
Severity
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
6.1 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CWE
  • CWE-1289 - Improper Validation of Unsafe Equivalence in Input
Assigner
Arista CNA under the mitre root
CNA scorecard B 87/100 over 116 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Arista Networks EOS Affected: 4.36.0F , ≤ 4.36.2F (custom)
Affected: 4.35.0F , ≤ 4.35.6M (custom)
Affected: 4.34.0F , ≤ 4.34.8M (custom)
Affected: 4.33.0F , ≤ 4.33.10M (custom)
Affected: 4.32.0F , < 4.33.0F (custom)
Affected: 1.0.0 , < 4.32.0F (custom)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "AWE 5000 Series",
            "AWE 7200R Series",
            "CloudEOS"
          ],
          "product": "EOS",
          "vendor": "Arista Networks",
          "versions": [
            {
              "lessThanOrEqual": "4.36.2F",
              "status": "affected",
              "version": "4.36.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.35.6M",
              "status": "affected",
              "version": "4.35.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.34.8M",
              "status": "affected",
              "version": "4.34.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.33.10M",
              "status": "affected",
              "version": "4.33.0F",
              "versionType": "custom"
            },
            {
              "lessThan": "4.33.0F",
              "status": "affected",
              "version": "4.32.0F",
              "versionType": "custom"
            },
            {
              "lessThan": "4.32.0F",
              "status": "affected",
              "version": "1.0.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003eswitch(config)#show bgp link-state summary\nBGP summary information for VRF default\nRouter identifier 0.0.0.1, local AS number 300\nNeighbor Status Codes: m - Under maintenance\n  Neighbor V AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   NlriRcd NlriAcc NlriAdv\n  12.0.0.3 4 300               82        83    0    0 01:02:33 Estab   0      0      1\n\nswitch#show adaptive-virtual-topology path | section Role:\nRole: pathfinder\u003c/pre\u003e"
            }
          ],
          "value": "switch(config)#show bgp link-state summary\nBGP summary information for VRF default\nRouter identifier 0.0.0.1, local AS number 300\nNeighbor Status Codes: m - Under maintenance\n  Neighbor V AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   NlriRcd NlriAcc NlriAdv\n  12.0.0.3 4 300               82        83    0    0 01:02:33 Estab   0      0      1\n\nswitch#show adaptive-virtual-topology path | section Role:\nRole: pathfinder"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "This vulnerability affects customers using Arista Pathfinder for WAN path selection with Border Gateway Protocol-Link State (BGP-LS) configured for Dynamic Path Selection (DPS). On affected platforms running Arista EOS with BGP-LS configured for DPS, an attacker who has established an authenticated BGP-LS session with the device can send a specially crafted BGP packet to cause incorrect WAN path selection and disrupt traffic forwarding."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-194",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-194 Fake the Source of Data"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          }
        },
        {
          "cvssV4_0": {
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1289",
              "description": "CWE-1289 Improper Validation of Unsafe Equivalence in Input",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T20:09:53.082Z",
        "orgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
        "shortName": "Arista"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/25034-security-advisory-0212"
        }
      ],
      "source": {
        "advisory": "Security Advisory 0212",
        "defects": [
          "2059581"
        ],
        "discovery": "INTERNAL"
      },
      "title": "Security Advisory 0212"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
    "assignerShortName": "Arista",
    "cveId": "CVE-2026-120979",
    "datePublished": "2026-11-10T20:09:53.082Z",
    "dateReserved": "2026-11-03T05:14:06.127Z",
    "dateUpdated": "2026-11-10T20:09:53.082Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-120979",
      "date": "2026-11-13",
      "epss": "0.00319",
      "percentile": "0.25235"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "platforms": [
                  "AWE 5000 Series",
                  "AWE 7200R Series",
                  "CloudEOS"
                ],
                "product": "EOS",
                "vendor": "Arista Networks",
                "versions": [
                  {
                    "lessThanOrEqual": "4.36.2F",
                    "status": "affected",
                    "version": "4.36.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.35.6M",
                    "status": "affected",
                    "version": "4.35.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.34.8M",
                    "status": "affected",
                    "version": "4.34.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.33.10M",
                    "status": "affected",
                    "version": "4.33.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThan": "4.33.0F",
                    "status": "affected",
                    "version": "4.32.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThan": "4.32.0F",
                    "status": "affected",
                    "version": "1.0.0",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "source": "psirt@arista.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "This vulnerability affects customers using Arista Pathfinder for WAN path selection with Border Gateway Protocol-Link State (BGP-LS) configured for Dynamic Path Selection (DPS). On affected platforms running Arista EOS with BGP-LS configured for DPS, an attacker who has established an authenticated BGP-LS session with the device can send a specially crafted BGP packet to cause incorrect WAN path selection and disrupt traffic forwarding."
          }
        ],
        "id": "CVE-2026-120979",
        "lastModified": "2026-11-12T19:24:37.847",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 8.1,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 5.2,
              "source": "psirt@arista.com",
              "type": "Secondary"
            }
          ],
          "cvssMetricV40": [
            {
              "cvssData": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "PRESENT",
                "attackVector": "NETWORK",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 6.1,
                "baseSeverity": "MEDIUM",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "LOW",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "HIGH",
                "vulnConfidentialityImpact": "NONE",
                "vulnIntegrityImpact": "HIGH",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "psirt@arista.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-11-10T20:18:53.073",
        "references": [
          {
            "source": "psirt@arista.com",
            "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/25034-security-advisory-0212"
          }
        ],
        "sourceIdentifier": "psirt@arista.com",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-1289"
              }
            ],
            "source": "psirt@arista.com",
            "type": "Secondary"
          }
        ]
      }
    }
  }
}



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