CVE-2026-73443

On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indefinitely. Replayed advertisements can be used to advertise stale VRRP state, for example to prevent a backup router from taking over the virtual gateway after the original master has gone down, resulting in a denial of service for hosts using the virtual gateway address.

Score

CVSS 4.0 5.3 Medium

Status

Awaiting Analysis - psirt@arista.com

Published

2026-09-16

Last modified

2026-09-17

Weaknesses

CWE-294

Affected products

• Eos (Arista Networks)

References

• https://www.arista.com/en/support/advisories-notices/security-advisory/24713-security-advisory-0157