CVE-2026-73458

On affected platforms running Arista EOS with authenticated Bidirectional Forwarding Detection (BFD) sessions configured, a specially crafted packet can cause the BFD session(s) to go down. This may result in undesirable network changes because various routing protocols monitor status on BFD session(s).

CVSS v3 8.2 HIGH

8.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.arista.com/en/support/advisories-notices/security-advisory/24710-security-advisory-0154

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-15 20:17

Updated : 2026-09-15 20:17

NVD link : CVE-2026-73458

Mitre link : CVE-2026-73458

CVE.ORG link : CVE-2026-73458

JSON object : View

Products Affected

No product.

CWE

CWE-303

Incorrect Implementation of Authentication Algorithm

{"id": "CVE-2026-73458", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73458", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-15T19:38:30.537124Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "psirt@arista.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.2, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 4.2, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "psirt@arista.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "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", "changes": [{"at": "4.36.2F", "status": "unaffected"}], "version": "4.36.0", "versionType": "custom", "lessThanOrEqual": "4.36.1F"}, {"status": "affected", "changes": [{"at": "4.35.6M", "status": "unaffected"}], "version": "4.35.0", "versionType": "custom", "lessThanOrEqual": "4.35.5M"}, {"status": "affected", "changes": [{"at": "4.34.8M", "status": "unaffected"}], "version": "4.34.0", "versionType": "custom", "lessThanOrEqual": "4.34.7M"}, {"status": "affected", "changes": [{"at": "4.33.9M", "status": "unaffected"}], "version": "4.33.0", "versionType": "custom", "lessThanOrEqual": "4.33.8M"}], "platforms": ["710 Series", "720D Series", "720XP/722XPM Series", "750X Series", "7010TX Series", "7020R/R4 Series", "7130 Series running EOS", "7170 Series", "7050X3/X4 Series", "7060X/X2/X4/X5/X6 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": "2026-09-15T20:17:43.160", "references": [{"url": "https://www.arista.com/en/support/advisories-notices/security-advisory/24710-security-advisory-0154", "source": "psirt@arista.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "psirt@arista.com", "description": [{"lang": "en", "value": "CWE-303"}]}], "descriptions": [{"lang": "en", "value": "On affected platforms running Arista EOS with authenticated Bidirectional Forwarding Detection (BFD) sessions configured, a specially crafted packet can cause the BFD session(s) to go down. This may result in undesirable network changes because various routing protocols monitor status on BFD session(s)."}], "lastModified": "2026-09-15T20:17:43.160", "sourceIdentifier": "psirt@arista.com"}