Denial of Service Vulnerability in Arista EOS Products by Arista Networks

CVE-2026-77190

What is CVE-2026-77190?

On platforms operating Arista EOS, a vulnerability exists allowing an unauthenticated attacker, positioned on the same network, to exploit configurations of PIM Sparse Mode with MLAG. By sending specially crafted messages, the attack can lead to the unexpected termination of the Pimsm agent. Although the system automatically restarts the Pimsm agent, persistent attacks can cause a cycle of continuous restarts, ultimately resulting in a denial of service and impacting network performance.

References