Arista EOS Vulnerability in RADIUS Proxy Feature with 802.1X Authentication

CVE-2026-73449

What is CVE-2026-73449?

On certain configurations of Arista EOS, a vulnerability allows a low-privileged attacker on an adjacent network segment to exploit the RADIUS proxy feature. This occurs specifically when both 802.1X port authentication and dynamic authorization are configured. An attacker can induce a RADIUS packet which may prevent critical dynamic authorization messages, such as Change-of-Authorization and Disconnect-Requests, from being enforced on authenticated 802.1X sessions. As a result, even when a disconnect command is issued by a RADIUS server or network access control system, the session may continue to remain authorized, posing a risk of unauthorized network access. The issue requires explicit configuration to manifest, and Arista has yet to identify any exploitation of this vulnerability in customer environments.

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