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CVE-2026-2379 Arista Networks CVE debrief

CVE-2026-2379 is a HIGH severity vulnerability in Arista EOS with a CVSS score of 8.2. 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.

Vendor
Arista Networks
Product
EOS
CVSS
HIGH 8.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-05
Original CVE updated
2026-06-05
Advisory published
2026-06-05
Advisory updated
2026-06-05

Who should care

Users of Arista EOS with hardware IPSec support and certain IPsec features enabled should be aware of this vulnerability and take recommended actions.

Technical summary

The vulnerability is caused by unexpected behavior in Arista EOS when certain IPsec features are enabled on affected platforms with hardware IPSec support. This can lead to sequence number mismatches between tunnel endpoints, potentially causing unstable communication.

Defensive priority

HIGH

Recommended defensive actions

  • Review and apply the security advisory from Arista: [ref-4](https://www.arista.com/en/support/advisories-notices/security-advisory/23419-security-advisory-0134)

Evidence notes

The CVE record [cve-org](https://www.cve.org/CVERecord?id=CVE-2026-2379) and NVD detail [nvd](https://nvd.nist.gov/vuln/detail/CVE-2026-2379) provide additional information on this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-2379 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-2379

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-2379 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-2379

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://www.arista.com/en/support/advisories-notices/security-advisory/23419-security-advisory-0134

    [email protected]

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.