Paper/Archive/CVE-2026-73437

CVE-2026-73437

Arista Networks EOS — 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/destinat

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
EOS4.36.0 – 4.36.1F–CNA
EOS4.35.0 – 4.35.5M–CNA
EOS4.34.0 – 4.34.7.1M–CNA
EOS4.33.0 – 4.33.9M–CNA

Scores by source

Arista (CNA)9.6CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Arista (CNA)6.5CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

advisoryarista.com/en/support/advisories-notices/security-advisory/24712-security-advisory-0156