Vulnerability in Arista Networks Eos
CVE-2026-73443
On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indefinitely. Replayed advertisements can be used to advertise stale VRRP state, for example to prevent a backup router from taking over the virtual gateway after the original master has gone down, resulting in a denial of service for hosts using the virtual gateway address.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.003 (19.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-73443?
- CVE-2026-73443 is a medium-severity vulnerability in Arista Networks Eos, classified under Authentication Bypass by Capture-replay. CVSS score: 4.7/10. Published 2026-09-16.
- How severe is CVE-2026-73443?
- Medium severity. CVSS v3 base score is 4.7 out of 10.