Arista NetworksCVE-2026-73443
Arista Networks EOS: denial of service
Medium5.3CVE-2026-73443 · Published Sep 16, 2026 · updated Sep 17, 2026
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 versions
| Package | Affected | Fixed in |
|---|---|---|
| EOS Product | >= 4.36.0, <= 4.36.1F | No fix yet |
| >= 4.35.0, <= 4.35.5M | No fix yet | |
| >= 4.34.0, <= 4.34.7M | No fix yet | |
| >= 4.33.0, <= 4.33.9M | No fix yet |
Details and references
- CVSS 4.0
- 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
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-294
More Arista Networks advisories
All Arista Networks| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Sep 16 | Arista Networks EOS: remote code execution | Critical9.2 | No fix yet |
| Sep 16 | Arista Networks EOS: secrets in logs | Medium6.0 | No fix yet |
| Sep 16 | Arista Networks EOS: out-of-bounds read | High7.1 | No fix yet |
| Sep 16 | Arista Networks EOS: secrets in logs | Low2.1 | No fix yet |
| Sep 16 | Arista Networks VeloCloud Edge: missing authentication | High8.7 | 5.2.0.0+3 more |
| Sep 16 | Arista Networks VeloCloud: out-of-bounds write | High8.2 | 5.2.0.0+3 more |