Dual Primary State Vulnerability in Arista EOS Affecting Network Operations
CVE-2026-73450
7HIGH
What is CVE-2026-73450?
In systems running Arista EOS configured with MLAG Dual Primary Detection, an unauthenticated attacker can exploit the network by sending specially crafted packets. This interference can cause the secondary switch to mistakenly enter a dual-primary state during a primary switch failure, resulting in err-disabled interfaces and a disruption of network traffic. Prompt action and careful configuration management are essential for securing affected systems.
Affected Version(s)
EOS 4.36.0 <= 4.36.1F
EOS 4.35.0 <= 4.35.5M
EOS 4.34.0 <= 4.34.7.1M
References
CVSS V4
Score:
7
Severity:
HIGH
Confidentiality:
None
Integrity:
Low
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None
Timeline
Vulnerability published
Vulnerability Reserved
Credit
This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.