CVE-2026-73443

On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indef

MEDIUM
4.7
CVSS Score
Published: September 16, 2026 at 06:47 PM UTC
Updated: September 17, 2026 at 07:16 PM UTC
1 product affected across 1 vendorArista EOS

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Severity
MEDIUM4.7
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indefinitely. Replayed advertisements can be used to advertise stale VRRP state, for example to prevent a backup router from taking over the virtual gateway after the original master has gone down, resulting in a denial of service for hosts using the virtual gateway address.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.33.0 ≤ v ≤ 4.33.9M4.34.0 ≤ v ≤ 4.34.7M4.35.0 ≤ v ≤ 4.35.5M4.36.0 ≤ v ≤ 4.36.1F4.33.04.34.04.35.04.36.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.7MEDIUMArista
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-294

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