CVE-2026-73463: Arista Networks Eos

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

On affected platforms running Arista EOS, when multiple gRPC Network Security Interface (gNSI) transports are configured, a race condition in the gNSI Authz service may cause a policy rotation to fail silently. An authenticated user whose access was revoked by the new policy may retain unauthorized access to gRPC interfaces. This does not affect Bootz. 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 4.36.0.1F; 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 4.33.8M; from 4.32.0F, up to and including 4.32.11M; from 4.31.0F, up to and including 4.31.10M

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