Vulnerability · Published Sep 14, 2026 · Assigned by Arista
CVE-2026-77191All of the CVEs covered in this advisory apply to affected platforms running Arista EOS with 802.1X authentication and authorization enabled and Access Control Lists (ACLs) configured for per-supplicant policy enforcement. An authenticated supplicant on an
Low 2.6
In plain English
A low-severity missing authorization in EOS from Arista Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).
Severity (CVSS 3.1)2.6Low
Exploit odds (30 days)0.2%top 86.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An authenticated supplicant on an adjacent network may bypass intended network authorization policy and send unrestricted traffic during a brief window (milliseconds to seconds) between the completion of the authentication phase and the full enforcement of its assigned ACL.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Arista Networks | EOS | 4.35.0 – through 4.35.0.3F4.34.0 – through 4.34.5M0.0.0 – through 4.33.7.1M |
Weakness: CWE-862 · Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N