CVE-2026-73446 Security Advisory 0160
An unauthenticated attacker can disrupt network traffic by tearing down IS-IS adjacencies on Arista EOS devices configured with IS-IS on broadcast interfaces.
- 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-2026-73446?
CVE-2026-73446 is a high-severity denial of service vulnerability in Arista Networks EOS, published on 15 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 IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.
Weakness: CWE-696
Which versions are affected by CVE-2026-73446?
How do I fix CVE-2026-73446?
No fix has been published for CVE-2026-73446 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-2026-73446 being exploited?
There is no known exploitation of CVE-2026-73446 in the wild and no public exploit code.
Sources
Also known as GHSA-gq4c-29w8-926p.