CVE-2026-73435: Arista Networks Eos

High severity, CVSS 8.2. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Arista Networks Eos: from 4.36.0F, up to and including 4.36.1F; from 4.35.0F, up to and including 4.35.5M; from 4.34.0F, up to and including 4.34.7M; from 4.33.0F, up to and including 4.33.9M; from 1.0.0, before 4.33.0F (fixed in 4.33.0F)

Published 2026-09-16. Last modified 2026-09-16.