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01 Record

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

MediumPUBLISHEDCNA: Arista
CNA base score5.3 CVSS v4.0CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

02 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 indef

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.27% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 19.5% of scored records. A rank, not a probability.
NVD base score
5.3 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS 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/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
NVD analysis status
Awaiting Analysis. NVD last modified this record on 2026-09-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-09-16 18:47Z1 MO AGO
Last updated
2026-09-17 18:33Z1 MO AGO
Reserved
2026-08-12
Assigning CNA
Arista
Record state
PUBLISHED
Severity
Medium (CVSS 5.3)
CNA CVSS 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
Weaknesses
  • CWE-294Authentication Bypass by Capture-replayBase
Data version
5.2
Document digest
34d826f5414ed2e6fe9928b2002ac3e2cd69a56b842520c2ebe9671ad20b05ab

05 Affected products

VendorProductVersionsPlatforms
Arista NetworksEOS4.36.0 to 4.36.1F, 4.35.0 to 4.35.5M, 4.34.0 to 4.34.7M, 4.33.0 to 4.33.9M710 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

06 References

07 Remediation

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Important: Upgrading alone is not sufficient. The replay protection introduced by the fix is disabled by default and must be explicitly enabled with the following new global configuration command after upgrading to a remediated release: switch(config)#vrrp ipv4 authentication anti-replay CVE-2026-73443 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