CVE-2026-2379

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

Published Jun 5, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Solution

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below. For more information about upgrading see: EOS User Manual: Upgrades and Downgrades https://www.arista.com/en/um-eos/eos-upgrades-and-downgrades CVE-2026-2379 has been fixed in the following releases: * 4.35.0F and later releases in the 4.35.x train * 4.34.4M and later releases in the 4.34.x train * 4.33.6M and later releases in the 4.33.x train * 4.32.8M and later releases in the 4.32.x train * 4.31.10M and later releases in the 4.31.x train


Vendor Workaround

There is no known mitigation for CVE-2026-2379. The recommended resolution is to upgrade to a remediated software version at your earliest convenience.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Arista
Arista eos
Vendors & Products Arista
Arista eos
Type Values Removed Values Added
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.
Title Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled
Weaknesses CWE-672
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Arista
Published
Updated
Jun 9, 2026, 2:36 PM
Reserved
Feb 11, 2026, 9:25 PM
Status
Awaiting Analysis
Published
Jun 5, 2026, 6:17 PM
Modified
Oct 26, 2026, 11:10 AM