Medium · published September 16, 2026
When specific platforms are using Arista EOS with a loose Unicast Reverse Path Forwarding (uRPF) configuration, certain traffic may not be subjected to the intended verification drop. Consequently, traffic that should be dropped based on these routes could still be processed and forwarded by the device.
This issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks.