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
Summary
| CVE | CVE-2026-73444 |
|---|---|
| State | PUBLISHED |
| Assigner | Arista |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-15 22:16:58 UTC |
| Updated | 2026-09-16 19:17:31 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 5.3 MEDIUM from [email protected]
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.002990000 probability, percentile 0.225560000 (date 2026-09-16)
Problem Types: CWE-303 | CWE-303 CWE-303 Incorrect Implementation of Authentication Algorithm
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 5.3 | MEDIUM | 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/E:X/C... |
| 4.0 | CNA | CVSS | 5.3 | MEDIUM | 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 |
| 3.1 | [email protected] | Secondary | 4.7 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
| 3.1 | CNA | CVSS | 4.7 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
CVSS v4.0 Breakdown
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Arista Networks | EOS | affected 4.36.0 4.36.1F custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 4.35.0 4.35.5M custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 4.34.0 4.34.7M custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected 4.33.0 4.33.9M custom | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
| CNA | Arista Networks | EOS | affected | 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.arista.com/en/support/advisories-notices/security-advisory/24713-securit... | [email protected] | www.arista.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: This issue was discovered internally by Arista. (en)
Additional Advisory Data
Solutions
CNA: 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
Workarounds
CNA: 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