On affected platforms running Arista EOS with VRRPv2 IP Authentication Header (IP-AH) authentication configured, an unauthenticated attacker with access to the layer 2 network segment on which VRRP is running could bypass VRRP authentication and claim the virtual router master role, enabling the attacker to intercept, modify, or discard traffic that hosts on the segment send to the virtual gateway address.

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Advisories

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Fixes

Solution

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-73444 has been fixed in the following releases: * 4.36.2F and later releases in the 4.36.x train * 4.35.6M and later releases in the 4.35.x train * 4.34.8M and later releases in the 4.34.x train * 4.33.10M and later releases in the 4.33.x train


Workaround

Restricting physical and logical access to VRRP-enabled segments reduces the attack surface. Additionally, migrating virtual routers from VRRP version 2 with authentication to VRRP version 3 removes the vulnerable code path: switch(config)# interface vlan 20 switch(config-if-vl20)# vrrp 1 ipv4 version 3

History

Tue, 15 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Description On affected platforms running Arista EOS with VRRPv2 IP Authentication Header (IP-AH) authentication configured, an unauthenticated attacker with access to the layer 2 network segment on which VRRP is running could bypass VRRP authentication and claim the virtual router master role, enabling the attacker to intercept, modify, or discard traffic that hosts on the segment send to the virtual gateway address.
Title On affected platforms running Arista EOS with VRRPv2 IP Authentication Header (IP-AH) authentication configured, an unauthenticated attacker with access to the layer 2 network segment on which VRRP is running could bypass VRRP authentication and claim the
Weaknesses CWE-303
References
Metrics cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Arista

Published:

Updated: 2026-09-15T21:11:37.625Z

Reserved: 2026-08-12T16:39:35.977Z

Link: CVE-2026-73444

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-15T22:16:58.493

Modified: 2026-09-15T22:16:58.493

Link: CVE-2026-73444

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses