CVE-2026-73443
published 2026-09-16CVE-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…
PriorityP426medium4.7CVSS 3.1
AVAACLPRNUINSCCNINAL
EPSS
0.27%
19.9th percentile
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.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| arista_networks | eos | 4.33.0 – 4.33.9M | — |
| arista_networks | eos | 4.34.0 – 4.34.7M | — |
| arista_networks | eos | 4.35.0 – 4.35.5M | — |
| arista_networks | eos | 4.36.0 – 4.36.1F | — |
CVSS provenance
nvdv3.14.7MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
nvdv4.05.3MEDIUMCVSS: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
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VulDB
Arista EOS up to 4.33.9M/4.34.7M/4.35.5M/4.36.1F VRRP authentication replay (WID-SEC-2026-3287)
vuldb·2026-09-17·CVSS 4.7
CVE-2026-73443 [MEDIUM] Arista EOS up to 4.33.9M/4.34.7M/4.35.5M/4.36.1F VRRP authentication replay (WID-SEC-2026-3287)
A vulnerability, which was classified as critical, has been found in Arista EOS up to 4.33.9M/4.34.7M/4.35.5M/4.36.1F. This impacts an unknown function of the component VRRP. The manipulation leads to authentication bypass by capture-replay.
This vulnerability is referenced as CVE-2026-73443. Remote exploitation of the attack is possible. No exploit is available.
GHSA
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 legitim
ghsa_unreviewed·2026-09-16
CVE-2026-73443 [MEDIUM] CWE-294 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 legitim
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.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-09-16
Published