CVE-2026-73459: Arista Networks Eos

High severity, CVSS 7.4. EPSS: 0.2% chance of exploitation in the next 30 days.

On affected platforms running Arista EOS with IS-IS configured, an unauthenticated attacker who can inject a specially crafted IS-IS LSP PDU can cause the legitimate LSP to be unexpectedly purged from the IS-IS link-state database. This may result in traffic loss.

Affected products

• Arista Networks Eos: from 4.36.0, up to and including 4.36.1F

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