CVE-2026-73450
Medium
Description
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.
SeverityMedium
CVSS6.9
Exploit probability—
ProductEOS
PublishedSep 16, 2026
First seenSep 16, 2026
Weakness typeCWE-345CWE-345
How to fix
Update
- Arista Networks EOS4.33.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Arista Networks EOS | 4.36.0 ≤ v ≤ 4.36.1F, 4.35.0 ≤ v ≤ 4.35.5M, 4.34.0 ≤ v ≤ 4.34.7.1M, 4.33.0 ≤ v ≤ 4.33.9M, v < 4.33.0 | 4.33.0 |
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