CVE-2026-73435

On affected platforms running Arista EOS with Open Shortest Path First version 2 (OSPFv2) configured, a specially crafted OSPFv2 packet from an unauthenticated attacker on the same broadcast segment, with OSPFv2 authentication configured can cause adjacency flapping and packet loss. The disruption can affect routing across the broader OSPF domain.

CVSS v3 8.2 HIGH

8.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.7

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://www.arista.com/en/support/advisories-notices/security-advisory/24727-security-advisory-0171

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-16 10:16

Updated : 2026-09-16 16:17

NVD link : CVE-2026-73435

Mitre link : CVE-2026-73435

CVE.ORG link : CVE-2026-73435

JSON object : View

Products Affected

No product.

CWE

CWE-345

Insufficient Verification of Data Authenticity

{"id": "CVE-2026-73435", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73435", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-16T15:28:37.069647Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "psirt@arista.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.2, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:H", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 4.7, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "psirt@arista.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 7.0, "Automatable": "NOT_DEFINED", "attackVector": "ADJACENT", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "psirt@arista.com", "affectedData": [{"vendor": "Arista Networks", "product": "EOS", "versions": [{"status": "affected", "version": "4.36.0F", "versionType": "custom", "lessThanOrEqual": "4.36.1F"}, {"status": "affected", "version": "4.35.0F", "versionType": "custom", "lessThanOrEqual": "4.35.5M"}, {"status": "affected", "version": "4.34.0F", "versionType": "custom", "lessThanOrEqual": "4.34.7M"}, {"status": "affected", "version": "4.33.0F", "versionType": "custom", "lessThanOrEqual": "4.33.9M"}, {"status": "affected", "version": "1.0.0", "lessThan": "4.33.0F", "versionType": "custom"}], "platforms": ["710 Series", "720D Series", "720XP/722XPM Series", "750X Series", "7010 Series", "7010X Series", "7020R/R4 Series", "7130 Series running EOS", "7150 Series", "7160 Series", "7170 Series", "7050X/X2/X3/X4 Series", "7060X/X2/X4/X5/X6 Series", "7250X Series", "7260X/X3 Series", "7280R/R2/R3/R4 Series", "7300X/X3 Series", "7320X Series", "7358X4 Series", "7368X4 Series", "7388X5 Series", "7500R/R2/R3 Series", "7800R3/R4 Series", "7700R4 Series", "AWE 5000 Series", "AWE 7200R Series", "CloudEOS", "cEOS-lab", "vEOS-lab", "CloudVision eXchange, virtual or physical appliance"], "defaultStatus": "unaffected"}]}], "published": "2026-09-16T10:16:51.363", "references": [{"url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24727-security-advisory-0171", "source": "psirt@arista.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "psirt@arista.com", "description": [{"lang": "en", "value": "CWE-345"}]}], "descriptions": [{"lang": "en", "value": "On affected platforms running Arista EOS with Open Shortest Path First version 2 (OSPFv2) configured, a specially crafted OSPFv2 packet from an unauthenticated attacker on the same broadcast segment, with OSPFv2 authentication configured can cause adjacency flapping and packet loss. The disruption can affect routing across the broader OSPF domain."}], "lastModified": "2026-09-16T16:17:15.077", "sourceIdentifier": "psirt@arista.com"}