CVE-2026-73450: Security Advisory 0161
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.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Affected Arista EOS platforms are exposed only when MLAG Dual Primary Detection is configured and an attacker can access the Dual Primary Detection network segment.
What conditions are required to trigger the traffic interruption?
An unauthenticated attacker must send specially crafted packets on the Dual Primary Detection segment while the MLAG primary switch fails. The secondary switch can then falsely detect a dual-primary condition and err-disable its interfaces.
What is the operational impact of a successful attack?
Interfaces on the secondary MLAG switch are err-disabled, resulting in a traffic interruption. The provided information describes availability impact and does not indicate confidentiality impact.