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EOS vulnerability

On affected platforms running Arista EOS with MACsec configuration, a specially crafted packet can cause the MACsec process to terminate unexpectedly. Continuous receipt of these packets with certain MACsec configurations can cause longer term disruption of dataplane traffic.

Published 6 Jan 2026Updated 7 Oct 20261 sources
CVSS 5.3
Overview Sources History

What happened

On affected platforms running Arista EOS with MACsec configuration, a specially crafted packet can cause the MACsec process to terminate unexpectedly. Continuous receipt of these packets with certain MACsec configurations can cause longer term disruption of dataplane traffic.

Affected versions

EOS: 4.34.3.0 through 4.34.3.1M (custom); 4.33.0 through 4.33.5M (custom); 4.32.0 through 4.32.7M (custom); 4.31.0 through 4.31.9M (custom); before 4.30.0 (custom) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.

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