CVE-2026-73443

EUVD-2026-80996

16.09.2026, 19:17

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.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	4.7 MEDIUM	ADJACENT_NETWORK	LOW	NONE	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: Unknown

Common Weakness Enumeration

CWE-294 - Authentication Bypass by Capture-replay
A capture-replay flaw exists when the design of the software makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

Vulnerability Media Exposure

[GERMAN] Arista EOS: Mehrere Schwachstellen
Ein Angreifer kann mehrere Schwachstellen in Arista EOS ausnutzen, um erweiterte Berechtigungen, sogar Administratorrechte, zu erlangen, beliebigen Code, einschließlich Root-Code, auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen sowie Denial-of-Service-Zustände herbeizuführen.
Published: 2026-09-09T22:00:00+00:00

References

https://www.arista.com/en/support/advisories-notices/security-advisory/24713-security-advisory-0157