CVE-2026-73438

Medium

Description

On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, an unauthenticated attacker on the same OSPFv3 broadcast domain can send a specially crafted set of packets that can cause the Ospf3 agent to restart unexpectedly. The crash results in the loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the broader OSPF domain until the agent recovers. This issue was reported externally by Dravanet Inc., and Arista is not aware of any malicious exploitation of this vulnerability in customer networks.

SeverityMedium
CVSS5.3
Exploit probability—
ProductEOS
PublishedSep 16, 2026
First seenSep 16, 2026
Weakness typeCWE-617CWE-617

How to fix

Update
  • Arista Networks EOS4.33.0F or later

Affected products

ProductAffected versionsFixed in
Arista Networks EOS4.36.0F ≤ v ≤ 4.36.1F, 4.35.0F ≤ v ≤ 4.35.5M, 4.34.0F ≤ v ≤ 4.34.7M, 4.33.0F ≤ v ≤ 4.33.9M, 1.0.0 ≤ v < 4.33.0F4.33.0F

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CVE-2026-73438 · EOS · Dark Radar