Medium severity · published Sep 16, 2026
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
4.7
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EO
EOS · Arista Networks
4.36.0 through 4.36.1F; 4.35.0 through 4.35.5M; 4.34.0 through 4.34.7M; 4.33.0 through 4.33.9M · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73443
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73443
www.arista.com
https://www.arista.com/en/support/advisories-notices/security-advisory/24713-security-advisory-0157
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