CVE-2026-73438 Security Advisory 0172
An unauthenticated attacker can crash the OSPFv3 agent on Arista EOS devices, disrupting routing adjacencies and causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73438?
CVE-2026-73438 is a high-severity denial of service vulnerability in Arista Networks EOS, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-617
Which versions are affected by CVE-2026-73438?
How do I fix CVE-2026-73438?
No fix has been published for CVE-2026-73438 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-73438 being exploited?
There is no known exploitation of CVE-2026-73438 in the wild and no public exploit code.
Sources
Also known as GHSA-665h-qpgj-xrwp.