CVE-2026-2379 MEDIUM

CVE-2026-2379: Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled

Vendor Arista Networks
Product EOS
Weakness CWE-672
Published June 5, 2026
Last update June 9, 2026

CVSS base score

5.9/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

On affected platforms with hardware IPSec support running Arista EOS with certain IPsec features enabled, EOS may exhibit unexpected behavior in specific cases. Physical interface flaps and certain agent restarts can cause IPsec tunnel re-establishment with existing Security Associations, resulting in sequence number mismatches between tunnel endpoints potentially causing unstable communication.

Key dates

02Disclosure timeline

June 5, 2026 CVE published
June 9, 2026 Record updated