Bypass Vulnerability in Arista EOS VRRPv2 IP-AH Authentication
CVE-2026-73444

5.3MEDIUM

Key Information:

Vendor

Arista Networks

Status
Eos
Vendor
CVE Published:
15 September 2026

What is CVE-2026-73444?

On specific Arista EOS platforms configured with VRRPv2 and IP Authentication Header (IP-AH), an unauthenticated attacker on the same Layer 2 network can bypass authentication mechanisms. This allows the attacker to assume the master role of the virtual router, potentially enabling interception, modification, or discarding of network traffic directed towards the virtual gateway address, which poses a substantial risk to network integrity and data confidentiality.

Affected Version(s)

EOS 710 Series 4.36.0 <= 4.36.1F

EOS 710 Series 4.35.0 <= 4.35.5M

EOS 710 Series 4.34.0 <= 4.34.7M

References

https://www.arista.com/en/support/advisories-notices/secu...
vendor-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

This issue was discovered internally by Arista.
.