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CVE-2026-73450: CWE-345: Insufficient Verification of Data Authenticity in Arista Networks EOS

0
Medium
VulnerabilityCVE-2026-73450cvecve-2026-73450cwe-345
Published: 09/16/2026 (09/16/2026, 02:32:45 UTC)
Source: CVE Database V5
Vendor/Project: Arista Networks
Product: EOS

Description

On affected platforms running Arista EOS with MLAG Dual Primary Detection configured, an unauthenticated attacker with access to the Dual Primary Detection network segment can send specially crafted packets to interfere with the dual-primary state. If the MLAG primary switch fails while these packets are present, the secondary switch incorrectly concludes it is in a dual-primary condition and err-disables its interfaces, leading to a traffic interruption.

CVSS v3.1

Score 6.9medium

Attack Vector
Adjacent Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
High
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:H

Affected software

Arista Networks

EOS

Affected versions
>=4.36.0 <=4.36.1F>=4.35.0 <=4.35.5M>=4.34.0 <=4.34.7.1M>=4.33.0 <=4.33.9M>=0.0.0 <4.33.0
GitHub Actionsmore threats →ai
arista-networks/eos
pkg:github/arista-networks/eos
Affected versions
>=0.0.0 <4.33.0>=4.33.0 <=4.33.9M>=4.34.0 <=4.34.7.1M>=4.35.0 <=4.35.5M>=4.36.0 <=4.36.1F

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/16/2026, 03:01:38 UTC

Technical Analysis

This vulnerability (CVE-2026-73450) involves insufficient verification of data authenticity (CWE-345) in Arista EOS when MLAG Dual Primary Detection is configured. An unauthenticated attacker on the relevant network segment can send specially crafted packets to disrupt the dual-primary state. Upon failure of the MLAG primary switch, the secondary switch may mistakenly believe it is in a dual-primary state and err-disable its interfaces, resulting in denial of service through traffic interruption. The CVSS 3.1 score is 6.9 (medium severity) with attack vector as adjacent network, high attack complexity, no privileges required, no user interaction, and scope changed. The impact is limited to integrity loss and high availability impact without confidentiality loss.

Potential Impact

The vulnerability can cause traffic interruption due to the secondary MLAG switch err-disabling its interfaces when it incorrectly detects a dual-primary condition. This results in denial of service affecting network availability. There is no confidentiality or direct data integrity compromise beyond the state interference.

Mitigation Recommendations

No explicit patch or remediation details are provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restricting access to the Dual Primary Detection network segment to trusted devices and monitoring for anomalous packets may reduce risk.

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Technical Details

Data Version
5.2
Assigner Short Name
Arista
Date Reserved
2026-08-12T16:42:47.921Z
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6aaa032c55bf5e2cf5e4d127

Added to database: 09/16/2026, 02:47:08 UTC

Last enriched: 09/16/2026, 03:01:38 UTC

Last updated: 09/16/2026, 04:01:54 UTC

Views: 6

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