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PatchSiren cyber security CVE debrief

CVE-2025-8873 Arista Networks CVE debrief

CVE-2025-8873 is a HIGH severity vulnerability in Arista EOS with IPsec configured. A specially crafted packet can cause the dataplane to stop processing all IPsec traffic. The control plane may detect this condition and attempt to reset the IPsec processing pipeline. After reset, traffic may not resume being processed. There is no impact to non-IPsec traffic or to IPsec traffic not originating or terminating on the system. This issue was reported by an Arista customer.

Vendor
Arista Networks
Product
EOS
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-04
Original CVE updated
2026-07-22
Advisory published
2026-06-04
Advisory updated
2026-07-22

Who should care

Users of Arista EOS with IPsec configured should be aware of this vulnerability and take steps to mitigate it.

Technical summary

On affected platforms running Arista EOS with IPsec configured, a specially crafted packet can cause the dataplane to stop processing all IPsec traffic. The control plane may detect this condition, and attempt to reset the IPsec processing pipeline. After reset traffic may not resume being processed. There is no impact to non-IPsec traffic or to IPsec traffic not originating or terminating on the system.

Defensive priority

HIGH

Recommended defensive actions

  • Apply the patch or workaround provided by the vendor (see resourceLinkAnnotations 'ref-4')
  • Review and update IPsec configurations to prevent exploitation

Evidence notes

The vendor is Arista, as indicated by the source reference (resourceLinkAnnotations 'ref-4') and evidence in the vendor field.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-8873 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-8873

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

  • CVE-2025-8873 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-8873

    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/22869-security-advisory-0127

    [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.