CVE-2026-73453: Arista Networks Eos

Critical severity, CVSS 10.0. EPSS: 0.7% chance of exploitation in the next 30 days.

An unauthenticated P4Runtime (Programming Protocol-Independent Packet Processors Runtime) client can achieve arbitrary code execution under certain conditions on affected platforms running Arista EOS configured with P4Runtime. P4Runtime is disabled by default in Arista EOS. By crafting a malicious packet during the initiation of a P4Runtime session, an attacker can obtain complete administrative control over the compromised switch. This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.

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, before 4.34.0F (fixed in 4.34.0F); from 4.32.0F, before 4.33.0F (fixed in 4.33.0F); from 4.31.0F, before 4.32.0F (fixed in 4.32.0F); …

Published 2026-09-16. Last modified 2026-09-17.