Vulnerability in Arista Networks Eos

CVE-2026-73437

On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay configured, an unauthenticated attacker with network access could send a crafted DHCP reply packet from an IP address that is not configured as a helper address, and the relay agent would forward it to clients without validating the source. This could allow the attacker to supply clients with malicious network configuration parameters, potentially resulting in traffic interception or denial of service for affected clients.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-73437?
CVE-2026-73437 is a critical-severity vulnerability in Arista Networks Eos, classified under Insufficient Verification of Data Authenticity. CVSS score: 9.6/10. Published 2026-09-15.
How severe is CVE-2026-73437?
Critical severity. CVSS v3 base score is 9.6 out of 10.