Vulnerability · Published Sep 16, 2026 · Assigned by Arista
CVE-2026-73438Security Advisory 0172
Medium 5.3
In plain English
A medium-severity security flaw in EOS from Arista Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Arista Networks | EOS | 4.36.0F – through 4.36.1F4.35.0F – through 4.35.5M4.34.0F – through 4.34.7M4.33.0F – through 4.33.9M1.0.0 – before 4.33.0F |
Weakness: CWE-617 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- Security Advisory 0172 vendor-advisory