Medium severity · published Jun 5, 2026
CVE-2026-2379
Arista EOS IPsec Tunnel Sequence Number Mismatch via Interface Flaps when Anti-Replay is Disabled
5.9
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 13% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EO
EOS · Arista Networks
4.34.0 through 4.34.3M; 4.33.0M through 4.33.5M; 4.32.0M through 4.32.7M; 4.31.0M through 4.31.9M; 4.30.0F before 4.31.0; 4.29.0F before 4.30.0; +2 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-2379
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-2379
www.arista.com
https://www.arista.com/en/support/advisories-notices/security-advisory/23419-security-advisory-0134
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