Vulnerability in Arista Networks Eos

CVE-2026-73450

On affected platforms running Arista EOS with MLAG Dual Primary Detection configured, an unauthenticated attacker with access to the Dual Primary Detection network segment can send specially crafted packets to interfere with the dual-primary state. If the MLAG primary switch fails while these packets are present, the secondary switch incorrectly concludes it is in a dual-primary condition and err-disables its interfaces, leading to a traffic interruption.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:H.

EPSS exploit prediction

EPSS: 0.002 (5.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-73450: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-73450?
CVE-2026-73450 is a medium-severity vulnerability in Arista Networks Eos, classified under Insufficient Verification of Data Authenticity. CVSS score: 6.9/10. Published 2026-09-16.
How severe is CVE-2026-73450?
Medium severity. CVSS v3 base score is 6.9 out of 10.