Vulnerability · Published Jun 5, 2026 · Assigned by Arista
CVE-2026-2379Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled
Medium 5.9
In plain English
A medium-severity security flaw 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).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Arista Networks | EOS | 4.34.0 – through 4.34.3M4.33.0M – through 4.33.5M4.32.0M – through 4.32.7M4.31.0M – through 4.31.9M4.30.0F – before 4.31.04.29.0F – before 4.30.04.28.0F – before 4.29.04.27.1F – before 4.28.0 |
Weakness: CWE-672 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N