CVE-2026-73459 Security Advisory 0160
An unauthenticated attacker can cause traffic loss by purging legitimate IS-IS LSPs from the link-state database on Arista EOS devices.
- 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-2026-73459?
CVE-2026-73459 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, an unauthenticated attacker who can inject a specially crafted IS-IS LSP PDU can cause the legitimate LSP to be unexpectedly purged from the IS-IS link-state database. This may result in traffic loss.
Weakness: CWE-354
Which versions are affected by CVE-2026-73459?
How do I fix CVE-2026-73459?
No fix has been published for CVE-2026-73459 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-2026-73459 being exploited?
There is no known exploitation of CVE-2026-73459 in the wild and no public exploit code.
Sources
Also known as GHSA-vq63-cff6-37q2.