CVE-2026-73449

What it is

On affected platforms running Arista EOS with both 802.1X port authentication and the RADIUS proxy feature configured with dynamic authorization, a low-privileged attacker on an adjacent network segment who induces a RADIUS packet through a configured RADIUS proxy client can prevent RADIUS dynamic authorization messages, including Change-of-Authorization (CoA) and Disconnect-Requests as defined in RFC 5176, from being applied to locally authenticated 802.1X sessions. This allows an endpoint session that a RADIUS server or network access control system has ordered disconnected to remain authorized on the network. Both 802.1X port authentication with dynamic authorization and RADIUS proxy with dynamic authorization must be explicitly configured for a deployment to be exposed to this issue. This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.

At a glance

Exploitability

Can be exploited from the same network segment with a low-privilege account. High risk of data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-09-14 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-16 19:08 UTC Last updatedMost recent change to the record

Details

Published

2026-09-14 22:16 UTC

Last modified

2026-09-16 19:08 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-290

Record status

Awaiting Analysis

Attack profile CVSS 4.0 · 5.9

Attack vector

Adjacent network

Complexity

Low

Attack requirements

Present

Privileges needed

Low

User interaction

None

Confidentiality

None

Integrity

High

Availability

None